Arduino Forum

Development => Other Hardware Development => Topic started by: liuzengqiang on Apr 24, 2015, 05:56 am

Title: [INFO] Making a programming jig for your designs
Post by: liuzengqiang on Apr 24, 2015, 05:56 am
I have recently developed an open source device based on arduino, with an ATMEGA1284P chip. I need to build a number of them and program/test them as well. I did some research and found this article from sparkfun to be quite useful:

For me, my device is rather large, not a small breakout board. So I need something for its size. The device has LCD, rotary encoder, RTC, SD card, etc. All need some tests before I flash a standard firmware. So I need some software that can flash at least two different firmware to a target with some human interactions. Luckly Nick Gammon has done all the great work with hex loader code. You can turn an arduino into a hex loader that programs fuse values on a target, and load hex files from an SD card to a target. Here is his repo:

I used his Atmega_hex_uploader code. It is interactive. You open the serial port and type in commands and see printouts. Very nicely done. Thanks Nick!

For my programmer, I thought about just using an arduino and a jumper wire. Then I have to solder male pins to my device's ICSP pins. It's a bit unnecessary and time-consuming, say if I need to program 100 devices (at least a couple extra hours to solder the pins). So I based on my original device design, moved the ICSP header to a different location, and placed a target ICSP header where the original device has ICSP header. I then kept the SD card, RTC, power supply, FTDI chip, and the MCU from the original design. The result is a device that can program other devices. I put it on standoffs. Since this device has the same screw hole locations, I can slide a newly-assembled device down the standoffs to make contact with the programmer. Then use nuts to hold the new device. I can then program it using serial port (fuses, hex code etc.) The programmer also has 2 push buttons. In the future, I will get rid of serial port and have the programmer standalone. If I press button 1, it will flash the target with one hex file that runs a series of tests. Then if all tests pass, I press the second button to flash the target with standard firmware and move on to the next board. I also have 4 LEDs (not yet soldered on) and a buzzer to show audio and visual indications of success and failure firmware flash. I also have a 8-dip switch row to further customize what I do with the target, such as program different standard firmware versions to the target for different variations of the device etc.

Here are some pictures:

Front side (left side has programmer's own ICSP header, right side is 6 pogo sticks)

Back side (SD card, MCU, two buttons, RTC, power supply):

Programmer with a target board on top:

Programmer with target board on the side (you can see the gold pogo sticks to the left of the right standoffs):

In the future, I will also write a more capable hex programmer with Nick's code to do:

I'll post some videos when I get a chance.