In the thread above about RS485 driver enable, always originated by me, some new and interesting (for me) techniques has been descripted to use...

In the thread above about RS485 driver enable, always originated by me, some new and interesting (for me) techniques has been descripted to use a "wide" (32- or 64-bits) hardware up/down counter to read effectively without disabling interrupts, as I usually have done in the past. If the processor supports native hardware 32-bits counter, the problem doesn't exist: most probably it can b...

does anyone know the protocol of Ford's DCL (data communications link) used on early '90s EEC-IVs? It's a two pin connection (it's not the...

does anyone know the protocol of Ford's DCL (data communications link) used on early '90s EEC-IVs? It's a two pin connection (it's not the normal flash self test flash code thing); from patents I've found it's probably a RS485 connection but I can find no info about the protocol used, other then a few scan tools that support it. Thanks

I am going to work on a project involving multiple devices on the same network(3 or more). One device will have user input and...

I am going to work on a project involving multiple devices on the same network(3 or more). One device will have user input and display(master). The other devices(slaves) will just collect sensory data and possibly process PID control loops. Data speeds are not a priority( < 1Mbps is okay). The master will read data from the two slave devices, and it may have to change manipulate data on the sla

I'm new to embedded Linux so this question could be very simple for many of you. Most probably, it isn't directly related to embedded world, but...

I'm new to embedded Linux so this question could be very simple for many of you. Most probably, it isn't directly related to embedded world, but to Linux OS generally. Anyway I think it is a common scenario in embedded applications. I'm going to develop a local/remote control of an electronic device. It communicates through a RS485 link. The local control will be a touch-screen display...

It's a long time I work with embedded platforms, however I never used a well-defined and "standard" data serialization format. I often had the...

It's a long time I work with embedded platforms, however I never used a well-defined and "standard" data serialization format. I often had the need to exchange data between platforms (Wifi, Ethernet, RS485...) and I always find a custom solution. I perfectly understood the problem with this approach. Keeping the two (or more) side synchronized is very difficult and error-prone. When the...

There are many commercial solutions for home-automation systems that are based on a two wires bus both for bidirectional data and for powering...

There are many commercial solutions for home-automation systems that are based on a two wires bus both for bidirectional data and for powering the modules. The number of connected modules could be high, 100 or more. What is the technology of those kind of buses? Are they simple half-duplex RS485? In this case, how the power can be distributed on the same wires of data? Is the protocol ...

Hi, We need a good embedded CPU board for our next project. It must be equipped with a relative fast processor, lots of RAM, Ethernet...

Hi, We need a good embedded CPU board for our next project. It must be equipped with a relative fast processor, lots of RAM, Ethernet (TCP/IP), optionally WiFi, Flash-card interface, at least 3 RS232/RS485 ports, some digital I/O, low power and last be not least low cost. The CPU board will be installed on our custom motherboard, where some of our custom hardware will be located. ...

I was searching for a reliable and simple protocol for a multidrop master/slave RS485 network. Reliable means it should work well if some...

I was searching for a reliable and simple protocol for a multidrop master/slave RS485 network. Reliable means it should work well if some errors occur, so it should provide retransmissions and detection of frame duplication. As soon as I read about HDLC in Normal Responde Mode, I loved it immediately. It is exactly what I wanted. http://en.wikipedia.org/wiki/High-Level_Data_Link_Cont...

Hello guys, I have asked to design a test system for an Ethernet enabled weather station. At this point, these weather stations are nothing...

Hello guys, I have asked to design a test system for an Ethernet enabled weather station. At this point, these weather stations are nothing but 2 PCs running Linux on it and they constantly read weather related information through some sensors. Eventually they will be replaced with a miniature embedded Linux device (yet to be designed!). I have worked extensively with 1/2 duplex RS485 n...

hello everyone, I have a RS485 based slave relay driver with 8 relays. The relays turn on at logic 0. Since the 89C51 has all ports as HIGH...

hello everyone, I have a RS485 based slave relay driver with 8 relays. The relays turn on at logic 0. Since the 89C51 has all ports as HIGH during reset, my relays should remain off. The problem that I am facing is that when I turn the power supply on, all the relays turn on momentarily and then back off. Is there a race condition during which the microcontroller is not gaining control of ...

I'm trying to find a way to make a connection between a custom MCU-based device (accessory) and an Android device (smartphone or tablet). The...

I'm trying to find a way to make a connection between a custom MCU-based device (accessory) and an Android device (smartphone or tablet). The goal is to exchange some data as with the old and good asyncronous serial (RS232/UART/RS485). My goal is to let the user configure the device through its smartphone, without power up a laptop or using local HMI (that will be surely worse than An...

I read the following page: http://xpcc.io/api/group__sab2.html The author suggests to use a CAN transceiver, instead of a RS485 half-duplex...

I read the following page: http://xpcc.io/api/group__sab2.html The author suggests to use a CAN transceiver, instead of a RS485 half-duplex transceiver, to create a serial multi-drop bus with nodes featuring normal UART peripherals. This should avoid the use of a third pin for direction control. What do you think? Does this solution works without problems? I think the control of the...

I find a board is very strong because it has so many things below: I am searching a board based on AT91SAM9G45 processor. 1. It must be all...

I find a board is very strong because it has so many things below: I am searching a board based on AT91SAM9G45 processor. 1. It must be all industry designed. Working temperature is -40-70 Celsius, not 0-70 Celsius. 2.Have 16 GPIOs, 5 USARTs, RS485, CAN, 2 methods of power which is +12V, ADC and other interface. 3.Supports 10.4"LCD, 4.3"LCD and 7" LCD. 4.Power consumption is below...

Looking for a processor board with: - USB Host port (Full-speed, USB v1.1 minimum), - 2x Serial ports (RS232, RS485), - 12-bit A/D converter...

Looking for a processor board with: - USB Host port (Full-speed, USB v1.1 minimum), - 2x Serial ports (RS232, RS485), - 12-bit A/D converter (under 2k samples/s) - Several general purpose I/O or parallel port. - Real-time clock (battery backed) and timers. - Low power consumption; few Watts. - Support an embedded operating system, like Linux preferably (but not essential). - Flash and RAM...

Hi all, I am going to use freeRTOS to do project, which has the following hardwar module. - 128x64 dot mono LCD graphic module - 4 key...

Hi all, I am going to use freeRTOS to do project, which has the following hardwar module. - 128x64 dot mono LCD graphic module - 4 key (direct key configure) - IrDA for printing - doing ADC via I2C interfaced ADC every 500ms The function of the device is; - User can use the key and display to read the DAC value - PC can request the ADC value / Key status / LCD status via RS485 / USB...

I have a piece of equipment that uses RS485 with RJ45 jacks and I was wondering if I needed special cabling with only 4 of the wires...

I have a piece of equipment that uses RS485 with RJ45 jacks and I was wondering if I needed special cabling with only 4 of the wires phyically connected in the jack or could I just use regular CAT5 Ethernet cabling with all eight wires present? The specs that I have for the cable only list 4 wires, but they are in the same order and place as a regular CAT5 Ethernet cable. The cable will go between...

I found that many RS485 transceivers can transmit data at the rate of 10 Mbps. My application requires that speed to communicate for a short...

I found that many RS485 transceivers can transmit data at the rate of 10 Mbps. My application requires that speed to communicate for a short distance (2 feet or 0.5 metres or so). Processors have UART which can transmit at 115kbps and not more. How do i acheive 10Mbps when the normal 32 bit processors could transmit at only 115kbps? I found one application note "AN3884-how fast can u go...

Hello! We are using a MC9S12NE64 for a RS485-> Ethernet router. we've experiencing problems with certain network switches. We get...

Hello! We are using a MC9S12NE64 for a RS485-> Ethernet router. we've experiencing problems with certain network switches. We get packet losses when we connect the router to some switches, the packages gets sent from the MC9S12NE64 but don't end up at the receiver. But with other switches the exact same application works fine. If connect a network hub between the MC9S12NE64 and the switch

I have two CPUs, master and slave. They are (will be, actually) connected with one SN75176B IC on each side, with two wires connecting...

I have two CPUs, master and slave. They are (will be, actually) connected with one SN75176B IC on each side, with two wires connecting them. After reset, the master will be in transmit mode, slave in recv mode. When the master sends a command to slave, the master will switch into recv mode and slave into transmit mode. Now, what happens while they are switching? At one moment, both si...

Dear All, I am using ARM9 based ATMEL AT91RM9200 microcontoller for a communication project. I am using a custom designed PCB. Problem is...

Dear All, I am using ARM9 based ATMEL AT91RM9200 microcontoller for a communication project. I am using a custom designed PCB. Problem is when i am receiving data via serial port, some times the controller got hang up. Need to restart every time. I am using RS485 communication and receive data via ttyS3 port. Presently i am receiving data in non-cannonical mode. controller have ...