[Logo] Anarduino and HopeRF Community Forum
  [Search] Search   [Recent Topics] Recent Topics   [Hottest Topics] Hottest Topics     [Groups] Back to home page 
[Register] Register / 
[Login] Login 
Gang Programming via bootloader  XML
Forum Index » Anarduino
Author Message
stevech



Joined: 07/07/2014 18:07:27
Messages: 91
Offline

I haven't read of this done before, but enclosed is a picture of 10 mega328P AVRs.
They are wired such that one run of the downloader updates all at once.
Almost silly, but the handshake responses in the stk500-like protocol are sent by just one of the 10. The other 9 serial TX pins are not connected.
But the timing works since all run the same clock and bootloader code.
The RX and DTR pins are daisychained.

I'm using this to speed development, while I'm improving my bootloader which does over the air (OTA) wireless remote reprogramming of the mega328s. That bootloader now does one at a time OTA reprogramming but not gang programming. I'm adding gang wireless remote reprogramming - because it takes too long to do these sequentially (non-gang). The tricky part is dealing with modules that get an error on wireless.

Anyway, the wired version of the gang reprogramming is simple.

Steve
photo:
https://plus.google.com/photos/102219196072599124106/albums/6068673010047626401?hl=en_US

This message was edited 1 time. Last update was at 10/10/2014 15:34:31

Charly86



Joined: 26/07/2014 06:39:50
Messages: 11
Offline

Steve,

Excellent idea, I never think it could work, only one in sync response, what a nice trick and idea

By the way I received these 7 ports USB hub with switch on each port. works amazing !!!!! even better of all I tested that do some disconnect on FTDI very often, never happened with this one, so happy, thank for the tip.

This message was edited 1 time. Last update was at 10/10/2014 15:39:22

stevech



Joined: 07/07/2014 18:07:27
Messages: 91
Offline

Charly86 wrote:Steve,

Excellent idea, I never think it could work, only one in sync response, what a nice trick and idea

By the way I received these 7 ports USB hub with switch on each port. works amazing !!!!! even better of all I tested that do some disconnect on FTDI very often, never happened with this one, so happy, thank for the tip.
I do notice on my 7 port switched hub, the USB 5V line out on each port, light load, is 4.8V, not 5V. This does affect some things... like the JTAGICE3. So you can apply an additional 5V source and it will override USB 5V.

I've been using the gang bootloader and it works fine. Even with one of ten that mistakenly had the FUSES set to clock/8, so it had the 115200 baud rate for bootloading despite the fuse mistake.

This message was edited 1 time. Last update was at 10/10/2014 17:51:14

 
Forum Index » Anarduino
Go to:   
Powered by JForum 2.1.9 © JForum Team