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There was discussion of the BX-24 and MIDI a few weeks ago, and it was mentioned that a different crystal would be needed to do MIDI. What crystal was it, specifically? And would it affect the ADC's horribly to change the crystal? I'm thinking of a couple apps that would take digital and/or analog inputs and output MIDI. -- -- Tom Igoe

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A 8mhz crystal should be able to give you the correct baud rate. You will have to calculate the baud rate and place it in the ubrr register yourself. You can do the opencom(1...) and then after this call, change the baud rate yourself to the new value by doing a: register.ubrr = 15 The calculation is ( (megahertz/16)/31250 ) - 1 Assuming the 31250 is the correct baud rate for the MIDI port (which I think it is). This ONLY works for COM1 Jack -----Original Message----- From: Tom Igoe <> To: <> Date: Tuesday, June 20, 2000 3:29 PM Subject: [BasicX] BX-24 and MIDI >There was discussion of the BX-24 and MIDI a few weeks ago, and it >was mentioned that a different crystal would be needed to do MIDI. >What crystal was it, specifically? And would it affect the ADC's >horribly to change the crystal? I'm thinking of a couple apps that >would take digital and/or analog inputs and output MIDI. >-- >-- >Tom Igoe > >------------------------------------------------------------------------ >Failed tests, classes skipped, forgotten locker combinations. >Remember the good 'ol days >http://click.egroups.com/1/5531/7/_/565855/_/961540185/ >------------------------------------------------------------------------

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Thanks, Jack. Two follow-up questions: 1. is there any way to do it for com3? 2. Does this screw up the serial programming on com1? >A 8mhz crystal should be able to give you the correct baud rate. > >You will have to calculate the baud rate and place it in the ubrr register >yourself. > >You can do the opencom(1...) and then after this call, change the baud rate >yourself to the new value by doing a: > >register.ubrr = 15 > >The calculation is ( (megahertz/16)/31250 ) - 1 > >Assuming the 31250 is the correct baud rate for the MIDI port (which I think >it is). > >This ONLY works for COM1 > >Jack -- -- Tom Igoe

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COM3 is bit banged using an interrupt at 4 times the baud rate. So for the 31250 this would be 125,000 interrupts per second. This is much higher than we would like on COM3 and would reduce the processor to little to no foreground processing. As for COM1, it will change the 115,200 for downloading up to 125,000 I dont think that the PC can handle this much change. I think it might be better to use 2 crystals and a tiny switch while you are developing and then when your project is done, then you can change it back. The other option is to buy a cheap serial card, and change ITS xtal or oscillator. Many of these us a 7.3728Mhz crystal or a 1.8432 crystal. You can change this to a 8mhz or 2mhz crystal and you would be running at 125,000 baud too! This would allow you to download and debug at the same speed. Jack -----Original Message----- From: Tom Igoe <> To: <> Date: Wednesday, June 21, 2000 6:16 AM Subject: Re: [BasicX] BX-24 and MIDI >Thanks, Jack. Two follow-up questions: > >1. is there any way to do it for com3? > >2. Does this screw up the serial programming on com1? >>A 8mhz crystal should be able to give you the correct baud rate. >> >>You will have to calculate the baud rate and place it in the ubrr register >>yourself. >> >>You can do the opencom(1...) and then after this call, change the baud rate >>yourself to the new value by doing a: >> >>register.ubrr = 15 >> >>The calculation is ( (megahertz/16)/31250 ) - 1 >> >>Assuming the 31250 is the correct baud rate for the MIDI port (which I think >>it is). >> >>This ONLY works for COM1 >> >>Jack >-- >-- >Tom Igoe > >------------------------------------------------------------------------ >Ãç´Ö¤È¤Ï¤¸¤á¤ë¡¢Ãç´Ö¤ò¸«¤Ä¤±¤ë¡¡£å¥°¥ë¡¼¥× >¡¡¡¡¡¡¡Ö¥°¥ë¡¼¥×¥á¡¼¥ë¤·¤Þ¤»¤ó¤«¡©¡× >¥µ¡¼¥¯¥ë¡¦Æ±Áë²ñ¡¦Æ±Î½¡¦¥Ó¥¸¥Í¥¹¡¦²È²¤Ç¤É¤¦¤¾¡ª >¡¡http://www.egroups.co.jp/info/features.html >http://click.egroups.com/1/3411/8/_/565855/_/961593371/ >------------------------------------------------------------------------

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Wow, so it becomes a complicated thing, especially if I'M introducing this to first-time students. So far this is the only thing I've found that the basic stamp can do that the BX24 can't. Probably the switch option is simplest. If anyone comes up with a simpler option that doesn't involve changing hardware in the PC, please share it... >COM3 is bit banged using an interrupt at 4 times the baud rate. So for the >31250 this would be 125,000 interrupts per second. This is much higher than >we would like on COM3 and would reduce the processor to little to no >foreground processing. > >As for COM1, it will change the 115,200 for downloading up to 125,000 I >dont think that the PC can handle this much change. I think it might be >better to use 2 crystals and a tiny switch while you are developing and then >when your project is done, then you can change it back. > >The other option is to buy a cheap serial card, and change ITS xtal or >oscillator. Many of these us a 7.3728Mhz crystal or a 1.8432 crystal. You >can change this to a 8mhz or 2mhz crystal and you would be running at >125,000 baud too! This would allow you to download and debug at the same >speed. -- -- Tom Igoe

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Look at Maxim's MAX3100 family. www.maxim-ic.com This would require using the SPI interface, which is easy, but can cause strange behavior unless done correctly. A 2MHz crystal would give you MIDI. Any baud rate is possible with the right crystal. Normally you use a 1.8432MHz crystal. Anything up to 4MHz will work, with scaled baud rates. Michael Fellinger -----Original Message----- From: Tom Igoe <> To: <> Date: Wednesday, June 21, 2000 10:18 AM Subject: Re: [BasicX] BX-24 and MIDI >Wow, so it becomes a complicated thing, especially if I'M introducing >this to first-time students. So far this is the only thing I've >found that the basic stamp can do that the BX24 can't. Probably the >switch option is simplest. If anyone comes up with a simpler option >that doesn't involve changing hardware in the PC, please share it... >>COM3 is bit banged using an interrupt at 4 times the baud rate. So for the >>31250 this would be 125,000 interrupts per second. This is much higher than >>we would like on COM3 and would reduce the processor to little to no >>foreground processing. >> >>As for COM1, it will change the 115,200 for downloading up to 125,000 I >>dont think that the PC can handle this much change. I think it might be >>better to use 2 crystals and a tiny switch while you are developing and then >>when your project is done, then you can change it back. >> >>The other option is to buy a cheap serial card, and change ITS xtal or >>oscillator. Many of these us a 7.3728Mhz crystal or a 1.8432 crystal. You >>can change this to a 8mhz or 2mhz crystal and you would be running at >>125,000 baud too! This would allow you to download and debug at the same >>speed. > >-- >-- >Tom Igoe > >------------------------------------------------------------------------ >SALESFORCE.COM MAKES SOFTWARE OBSOLETE >Secure, online sales force automation with 5 users FREE for 1 year! >http://click.egroups.com/1/2658/8/_/565855/_/961604286/ >------------------------------------------------------------------------

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I guarantee you that the Stamp cannot receive MIDI commands while processing anything else. Since MIDI is a asyncronous event you dont know when the midi will come at you. Try using COM1 with the standard 7.3728Mhz crystal. Do the OpenCOM(1..) to whatever baud rate you want and then perform the statement: register.ubrr = 14 This should set the baud rate to 7372800/16/(14+1) = 30,720 baud. This is 1.7% off of the "correct" midi baud rate of 31250, but the UART in the MIDI device should be able to deal with this percentage error. Most UARTS work up to 5% error. Jack -----Original Message----- From: Tom Igoe <> To: <> Date: Wednesday, June 21, 2000 9:18 AM Subject: Re: [BasicX] BX-24 and MIDI >Wow, so it becomes a complicated thing, especially if I'M introducing >this to first-time students. So far this is the only thing I've >found that the basic stamp can do that the BX24 can't. Probably the >switch option is simplest. If anyone comes up with a simpler option >that doesn't involve changing hardware in the PC, please share it... >>COM3 is bit banged using an interrupt at 4 times the baud rate. So for the >>31250 this would be 125,000 interrupts per second. This is much higher than >>we would like on COM3 and would reduce the processor to little to no >>foreground processing. >> >>As for COM1, it will change the 115,200 for downloading up to 125,000 I >>dont think that the PC can handle this much change. I think it might be >>better to use 2 crystals and a tiny switch while you are developing and then >>when your project is done, then you can change it back. >> >>The other option is to buy a cheap serial card, and change ITS xtal or >>oscillator. Many of these us a 7.3728Mhz crystal or a 1.8432 crystal. You >>can change this to a 8mhz or 2mhz crystal and you would be running at >>125,000 baud too! This would allow you to download and debug at the same >>speed. > >-- >-- >Tom Igoe > >------------------------------------------------------------------------ >SALESFORCE.COM MAKES SOFTWARE OBSOLETE >Secure, online sales force automation with 5 users FREE for 1 year! >http://click.egroups.com/1/2658/8/_/565855/_/961604286/ >------------------------------------------------------------------------

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Hi, I need to control a few pots on a piece of gear remotely and rather than using motor driven pots I would prefer to use some sort of IC. Does anyone have any ideas of pointers? Regards, Jean-Michel.

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On Thu, 22 Jun 2000 16:48:16 +0800, Jean-Michel Howland <> wrote: > Does anyone have any ideas of pointers? Dallas makes an IC pot in their 1-wire family. www.dalsemi.com Later, Jon -------------------------------------------------------------- Jon Hylands http://www.huv.com/jon Project: Micro Seeker (Micro Autonomous Underwater Vehicle) http://www.huv.com

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>> Does anyone have any ideas of pointers? > >Dallas makes an IC pot in their 1-wire family. > >www.dalsemi.com Thanks Jon, delsemi has the perfect solution! Regards, Jean-Michel.

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Hi all, It's me again with yet another problem. I'm trying to read data in from a tiny trackball (http://www.vmapa.com/tb-top.jpg) and write out the data to my LCD. Problem is I can only open Com3 once by the looks of it. I thought you could define Com3 with different queues to many different pins as I have done in the following code but with no luck. Ideas? Regards, Jean-Michel. Option Explicit Private Const LCD_Queue_Length As Integer = 30 Private Const TB_Queue_Length As Integer = 30 Private LCD_Serial_Output_Buffer(1 to LCD_Queue_Length) As Byte Private TB_Serial_Input_Buffer(1 to TB_Queue_Length) As Byte Sub Main() Dim MouseData(1 To 6) As byte Dim MouseDataStr As String Call LCD_Open_Serial_Port Call TB_Open_Serial_Port Call LCD_Cursor_Off LCD_Clear_Screen Do If StatusQueue(TB_Serial_Input_Buffer) Then Call GetQueue(TB_Serial_Input_Buffer, MouseData, 6) MouseDataStr = CStr(MouseData(1)) & ":" & _ CStr(MouseData(2)) & ":" & _ CStr(MouseData(3)) & ":" & _ CStr(MouseData(4)) & ":" & _ CStr(MouseData(5)) & ":" & _ CStr(MouseData(6)) Call LCD_Send_String(MouseDataStr) End If Loop End Sub Private Sub LCD_Open_Serial_Port() Call OpenQueue(LCD_Serial_Output_Buffer, LCD_Queue_Length) Call DefineCom3(0,5,&H88) Call OpenCom(3, 9600, LCD_Serial_Output_Buffer, LCD_Serial_Output_Buffer) End Sub Private Sub TB_Open_Serial_Port() Call OpenQueue(TB_Serial_Input_Buffer, TB_Queue_Length) Call DefineCom3(6,0,&H07) Call OpenCom(3, 1200, TB_Serial_Input_Buffer, TB_Serial_Input_Buffer) End Sub Private Sub LCD_Clear_Screen() Call LCD_Send_Byte(12) End Sub Private Sub LCD_Cursor_Off() Call LCD_Send_Byte(25) Call LCD_Send_Byte(0) End Sub Private Sub LCD_Send_String(ByVal Value As String) Call PutQueueStr(LCD_Serial_Output_Buffer, Value) End Sub Private Sub LCD_Send_Byte(ByVal Value As Byte) Call PutQueue(LCD_Serial_Output_Buffer, Value, 1) End Sub

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Will try that too. Most of the time, with the stamp, we don't make projects to receive midi. We use it only as a midi controller, outputting messages in response to sensors. Works very well for that. I think the basicx will too, if I can get one of these solutions to work. Will post here if I get good results, in grateful appreciation. >I guarantee you that the Stamp cannot receive MIDI commands while processing >anything else. Since MIDI is a asyncronous event you dont know when the >midi will come at you. > >Try using COM1 with the standard 7.3728Mhz crystal. Do the OpenCOM(1..) to >whatever baud rate you want and then perform the statement: > >register.ubrr = 14 > >This should set the baud rate to 7372800/16/(14+1) = 30,720 baud. > >This is 1.7% off of the "correct" midi baud rate of 31250, but the UART in >the MIDI device should be able to deal with this percentage error. Most >UARTS work up to 5% error. -- -- Tom Igoe

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On Thu, 22 Jun 2000 21:55:46 +0800, Jean-Michel Howland <> wrote: > >Dallas makes an IC pot in their 1-wire family. > > > >www.dalsemi.com > > Thanks Jon, delsemi has the perfect solution! I don't know if you saw it, but I have posted a pretty complete Dallas 1-wire interface for the BX-24 to the files area... It should work pretty well with multiple pots, and you can even throw in an 1820 or two to measure temperature :-) Later, Jon -------------------------------------------------------------- Jon Hylands http://www.huv.com/jon Project: Micro Seeker (Micro Autonomous Underwater Vehicle) http://www.huv.com

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At 10:10 PM 6/22/00 +0800, you wrote: >Hi all, > >It's me again with yet another problem. > >I'm trying to read data in from a tiny trackball >(http://www.vmapa.com/tb-top.jpg) and write out the data to my >LCD. Problem is I can only open Com3 once by the looks of it. Can you use com1 and com3 instead of opening two com3's? Just a thought... Duncan

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Tried Jack's solution below to do MIDI out on a BX-24 today, and got mighty close. On a synth I've got, and a separate MIDI interface box, both would flash their "MIDI received" LED's at me when I sent in bytes, but received bad data. Not sure why, all I can figure is that 1.5% made a difference. Here's the code: Sub Main() dim note as byte debug.print "starting" call DefineCom3 (11, 12, bx1000_1000) call OpenSerialPort(3, 19200) register.ubrr = 14 call putPin(25, 1) do for note = 36 to 96 call putByte(144) call putByte(note) call putByte(64) call putPin(25, 0) call delay(1.0) call putByte(144) call putByte(note) call putByte(0) call putPin(25, 1) call delay(1.0) next loop End Sub (note: serialport.bas was used as well...) Instead of 144,36,64, 144 36, 0, etc. I got things like 128, 44, 0, 164, 0, 30 etc. No rhyme or reason. Any thoughts, anyone? Meanwhile I'm going to look into Michael Fellinger's MAX3100 solution... >Try using COM1 with the standard 7.3728Mhz crystal. Do the OpenCOM(1..) to >whatever baud rate you want and then perform the statement: > >register.ubrr = 14 > >This should set the baud rate to 7372800/16/(14+1) = 30,720 baud. > >This is 1.7% off of the "correct" midi baud rate of 31250, but the UART in >the MIDI device should be able to deal with this percentage error. Most >UARTS work up to 5% error. -- -- Tom Igoe

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ONLY COM1 will work in this manner. The UBRR function is for setting the COM1 port. Jack -----Original Message----- From: Tom Igoe <> To: <> Date: Monday, June 26, 2000 1:51 PM Subject: Re: [BasicX] BX-24 and MIDI >Tried Jack's solution below to do MIDI out on a BX-24 today, and got >mighty close. On a synth I've got, and a separate MIDI interface >box, both would flash their "MIDI received" LED's at me when I sent >in bytes, but received bad data. Not sure why, all I can figure is >that 1.5% made a difference. Here's the code: > >Sub Main() > dim note as byte > debug.print "starting" > > call DefineCom3 (11, 12, bx1000_1000) > call OpenSerialPort(3, 19200) > > register.ubrr = 14 >call putPin(25, 1) > do > for note = 36 to 96 > call putByte(144) > call putByte(note) > call putByte(64) > call putPin(25, 0) > call delay(1.0) > call putByte(144) > call putByte(note) > call putByte(0) > call putPin(25, 1) > call delay(1.0) > next > > loop > >End Sub > >(note: serialport.bas was used as well...) > >Instead of 144,36,64, 144 36, 0, etc. I got things like 128, 44, 0, >164, 0, 30 etc. No rhyme or reason. > >Any thoughts, anyone? > >Meanwhile I'm going to look into Michael Fellinger's MAX3100 solution... > >>Try using COM1 with the standard 7.3728Mhz crystal. Do the OpenCOM(1..) to >>whatever baud rate you want and then perform the statement: >> >>register.ubrr = 14 >> >>This should set the baud rate to 7372800/16/(14+1) = 30,720 baud. >> >>This is 1.7% off of the "correct" midi baud rate of 31250, but the UART in >>the MIDI device should be able to deal with this percentage error. Most >>UARTS work up to 5% error. > >-- >-- >Tom Igoe > >------------------------------------------------------------------------ >IT Professionals: Match your unique skills with the best IT projects at >http://click.egroups.com/1/3381/8/_/565855/_/962052601/ >------------------------------------------------------------------------

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COM1 is inverted remember so you would need to account for this in your hardware for the MIDI port. Jack -----Original Message----- From: Tom Igoe <> To: <> Date: Monday, June 26, 2000 3:33 PM Subject: Re: [BasicX] BX-24 and MIDI >>ONLY COM1 will work in this manner. The UBRR function is for setting the >>COM1 port. >> >>Jack > >I thought that; got similar results off com1, that's when I switched >to com3. Sorry, should have mentioned that. >-- >-- >Tom Igoe > >------------------------------------------------------------------------ >IT Professionals: Match your unique skills with the best IT projects at >http://click.egroups.com/1/3381/8/_/565855/_/962058760/ >------------------------------------------------------------------------

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