ESD problems with PIC 16F88

Started by Anonymous in comp.arch.embedded12 years ago 14 replies

I have built a number of battery operated circuits using PIC16F88s. They are housed in a plastic case with a socket to plug in a...

I have built a number of battery operated circuits using PIC16F88s. They are housed in a plastic case with a socket to plug in a serial connection for controlling LED outputs by RS232 comms. Sometimes when you touch the socket with your finger, the PIC responds in a manner suggesting that it has received some random data on the Rx pin of the USART. The problem occurs much more frequently ...


5 volt supply straight from 240v AC mains

Started by techie_alison in comp.arch.embedded13 years ago 34 replies

Hi, Please may I ask what the arrangement is when you see a single LED powered straight off of a mains power supply without any transformers...

Hi, Please may I ask what the arrangement is when you see a single LED powered straight off of a mains power supply without any transformers or switch mode circuitry? In other words, totally uninsulated or regulated. I have an old computer with an external hard disk which needs about 30 seconds to spin-up before the computer. With a small timing circuit, 555, or using a PIC even (have ...


powering a LED through the human skin

Started by Lyn in comp.arch.embedded13 years ago 37 replies

I am trying to solve a problem of having wires going up to an MP3 player to the earpiece. I also didn't want the weight of batteries, e.g. via...

I am trying to solve a problem of having wires going up to an MP3 player to the earpiece. I also didn't want the weight of batteries, e.g. via a Bluetooth or other wireless head set. I did an experiment where I used conductive paint to mark out some tracks on my skin to replace wires. The conductive paint is very flexible (I put it on my hand which flexed a lot ) and there seemed to be enou...


Delay Routine: Fully-portable C89 if possible

Started by Martin Wells in comp.arch.embedded12 years ago 100 replies

I'm doing an embedded systems project which consists of taking input from the user via simple buttons, and giving output in the form...

I'm doing an embedded systems project which consists of taking input from the user via simple buttons, and giving output in the form of lighting LED's. So far, I've written the program as fully-portable C89, and I intend to keep it that way as much as possible. Obviously, I'll have microcontroller-specific parts to it such as: void SetPinHigh(unsigned) { /* Must call microcontroller...


Wireless Power Transfer

Started by Eric in comp.arch.embedded14 years ago 11 replies

Have have an interesting problem. I need to transfer power (7V @ 20mA approx. 140mW) across a 2-3 inch air gap without using a wire. It...

Have have an interesting problem. I need to transfer power (7V @ 20mA approx. 140mW) across a 2-3 inch air gap without using a wire. It will be in a high vibration and dirty (ie. greasy, oilly) evironment. Here are my ideas: 1) create an air gap transformer 2) use super bright LED's and a Solar panel Does any one have any experience or knowledge in this area that could offer s...


Sony ACX705AKM LCD users/ spec questions?

Started by Bo in comp.arch.embedded13 years ago 2 replies

We are planning to use this LCD in an embedded project with a Gumstix processor and I am having more than a little trouble getting support from...

We are planning to use this LCD in an embedded project with a Gumstix processor and I am having more than a little trouble getting support from Sony. The 1st problem is knowing how to drive the LED backlight. The spec simply says 15mA current source, but it does not give any details about the forward drops in the backlight. So I don't know what the minimum voltage is. If anyone ha...


Bi-color SMD leds: red and infrared?

Started by msr in comp.arch.embedded8 years ago 2 replies
LED

Hi everyone, Im looking for SMD leds with red and infrared wavelenghts. Both in a single package. It's to be used in a pulse oxymeter. Do...

Hi everyone, Im looking for SMD leds with red and infrared wavelenghts. Both in a single package. It's to be used in a pulse oxymeter. Do you know a company that offers this kind of LED/packages? In other words, do you know where to buy leds for pulse oximeters? Any suggestion would be greatly appreciated. Thanks --------------------------------------- Posted through ...


General Idea for a USB related proyect

Started by jarguello in comp.arch.embedded10 years ago

Hello there. I´m new working with microcontroller, at the moment never try using USB. I´planning to develop a interface PC-USB proyect...

Hello there. I´m new working with microcontroller, at the moment never try using USB. I´planning to develop a interface PC-USB proyect (using atmel ATMEGA16), where a infrared-led acts as a light analog sensor, depending on the leght of hte light disturbance the microcontroler has to distinguish between two posible paths, i was thinking on sending this signal to a PC-host software where the ...


Could PIC handle this?

Started by David in comp.arch.embedded15 years ago 35 replies

Could a PIC handle interfacing via rs232 with a GPS unit, and comparing the location against a list of ~5000 stored positions, and alerting...

Could a PIC handle interfacing via rs232 with a GPS unit, and comparing the location against a list of ~5000 stored positions, and alerting (LED/LCD) if any points are considered close enough (~1-2km, using haversine formula, perhaps)? I guess the points would have to be stored on a CF/MMC card. They would be updated/changed time to time...


Newbie PWM problem with PIC 16F627

Started by Deep Reset in comp.arch.embedded15 years ago 2 replies

I'm having problems with the PWM module on a PIC 16F627, and I wondered if anyone could help please. The PIC is clocked at 4MHz, and I've got...

I'm having problems with the PWM module on a PIC 16F627, and I wondered if anyone could help please. The PIC is clocked at 4MHz, and I've got 6 LEDs on port B, including RB3/CCP1. I can write simple light-chaser programs, but I'm trying to dim the LED on CCP1, but it is either on, or its off. My program looks like this: RESET MOVLW B'00000111' ;Disable Comparator modules ...


STR9 Timer Prescaler Problem

Started by Nick Harold in comp.arch.embedded10 years ago

Hi All, I've revisted some of the STR9 Firmware Library Examples and the TIM Example2 works fine and is straight forward but stops working...

Hi All, I've revisted some of the STR9 Firmware Library Examples and the TIM Example2 works fine and is straight forward but stops working properly when you increase the timer prescale value (TIM_CR2-> CC). The example sets a timer prescale value of 0x20 and an LED is toggled. Increasing the prescale value slows the toggle rate, up until a certain prescale value. At around 0x45 (or something)


AVRStudio 4 with matrix keypad

Started by Joe Butler in comp.arch.embedded14 years ago 1 reply

I'd like to be able to use a virtual matrix keypad with AVRStudio 4. It's a bit awkward setting up stumuli files, since these need to be...

I'd like to be able to use a virtual matrix keypad with AVRStudio 4. It's a bit awkward setting up stumuli files, since these need to be synchronised with the keypad scanning. Has anyone got any ideas? I think it might be possible with a plugin. This guy's got a virtual LCD and LED plugin, but it didn't seem to work out of the box and may have caused my Windows Explorer to crash. http...


mA-hour meter

Started by Anonymous in comp.arch.embedded14 years ago 3 replies

I'm working on an amp-hour meter (actually milliamp-hour) and am planning on using an Allegro current sensor to measure current from...

I'm working on an amp-hour meter (actually milliamp-hour) and am planning on using an Allegro current sensor to measure current from a discharging battery under load. I plan on displaying the accumulated amp-hours on an LED display, and a PIC will be running the show. Is the Allegro the best method for doing this, or is there another way? I haven't gotten into it yet, but it looks like the ...


Xilinx V4 Custom IP

Started by Anonymous in comp.arch.embedded12 years ago

I am trying to write a simple custom IP to get started. I just want to control the LED on my evaluation board. I want to be able to write a...

I am trying to write a simple custom IP to get started. I just want to control the LED on my evaluation board. I want to be able to write a custom IP to prove to myself I am doing it correctly instead of using the IP provided. I am using a Memec V4 UltraController II eval board and EDK 9.1 SP2. I created a template IP using EDK and then wrote my VHDL code to control the LEDs. The proble...


16F84 and time between two flash

Started by dario in comp.arch.embedded15 years ago 1 reply

Hi, I want read precise time elapsed between two flash of a red led and show this time on a 8/16 char matrix display. The value has to be very...

Hi, I want read precise time elapsed between two flash of a red led and show this time on a 8/16 char matrix display. The value has to be very accurate. Time range goes from 0.2 sec to 15 sec. I would like do this by a 16F84 in basic language (picbasic pro compiler) Im a VB programmer and Im a newbie in a microcontroller programming Any suggestion for code and circuit for phototra...


Atmel Programmer

Started by --|-- in comp.arch.embedded16 years ago 5 replies

http://www.lancos.com/e2p/avrisp-stk200.gif ok i built the above programmer using an at90s2312 also completed crystal circut...... anyhow...

http://www.lancos.com/e2p/avrisp-stk200.gif ok i built the above programmer using an at90s2312 also completed crystal circut...... anyhow long story short, i can read security descriptors, but anything else failes the led also never lights up, the par port is giving me 4.6 volts and 96ma but the power drastically drops when i run an action, vcc to the atmel only carries 2.1 volts or so ....


newbie help, Please

Started by Anonymous in comp.arch.embedded14 years ago 3 replies

Ok, so I decided to build a LC meter based on 89c2051 microcontroller. I have 35 yrs experience in electronics and I have limited...

Ok, so I decided to build a LC meter based on 89c2051 microcontroller. I have 35 yrs experience in electronics and I have limited experience flashing at90s2313 with a home made programmer. So I made the python programmer and used py2051.exe to program the 89c2051. see http://www.geocities.com/dinceraydin/8051/index.html I cannot get the blink led test circuit to work.... I do get a b...


iPod Mini Housing/Case

Started by Anonymous in comp.arch.embedded14 years ago 2 replies

I'm looking for a housing/case for a low volume product. The product will be a 9cm x 5cm x 2cm PCB with USB connector and some LED indicators....

I'm looking for a housing/case for a low volume product. The product will be a 9cm x 5cm x 2cm PCB with USB connector and some LED indicators. Anyone know of a company that could supply me with something like the rather cool iPod Mini housing ? I want to avoid large upfront tooling etc costs. TIA, Hugh,,


Serial Port/PLD communcation. Suggestions?

Started by Anonymous in comp.arch.embedded13 years ago 9 replies

I am working on a very simple hardware project and would like to develop serial port controls, but I'm having a little bit of trouble starting...

I am working on a very simple hardware project and would like to develop serial port controls, but I'm having a little bit of trouble starting out. The project is the following: I have built an LED lamp with 8 seperate light-up sections controlled by a PLD. Each time the PLD clocks, it assigns the value of the input (either high or low) to one of the output pins (0 through 7), which subseq...


Cheap debugging tools, software UART

Started by Jim Stewart in comp.arch.embedded8 years ago 11 replies

Watching all this discussion about debugging with an LED and such, I was wondering if anyone else writes software UARTS for debug info. I've...

Watching all this discussion about debugging with an LED and such, I was wondering if anyone else writes software UARTS for debug info. I've written a 9600 baud tx-only UART for AVR's in 35 assembly instructions. The data out can be inverted so that you can connect the tx I/O pin directly to your terminal without an inverter or driver. Timing is by software timing loops so interrupts...