Author Topic: USB programmer for 3.3 volt product using Digispark  (Read 1185 times)

Digital Larry

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USB programmer for 3.3 volt product using Digispark
« on: April 06, 2018, 11:41:25 am »
I have a Digispark and I saw the EEPROM programmer shield for it.  Here's my project that I'm about to start:

1) Connect from USB to the Digispark with is connected to the i2c bus on a 3.3 volt system, to program a 24LC32A EEPROM.
2) Allow a programming interface to an open-source Java program I have written.  My program generates HEX files which I want to program directly to the EEPROM.

I see there is an "Ardulink" open source Java project that might be a way to integrate into my own project.

Any other suggestions are welcome whether high or low level.


Digital Larry

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Re: USB programmer for 3.3 volt product using Digispark
« Reply #1 on: April 06, 2018, 05:18:40 pm »
Looks like I can connect the Digispark directly to the GND and I2C lines of the 3.3V system.  I looked at the schematic of the EEPROM shield and it's just got a couple of pullups to +5 from the Digispark which is also powering the EEPROM chip itself.  So if the outputs are operating open-collector or open-drain it should work fine that way.

I also found the EEPROM example code but I'm going to need to investigate this a bit because it's not obvious how one would transfer a file, or bytes one by one over USB from an application to be written into the EEPROM.

supriyala

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Re: USB programmer for 3.3 volt product using Digispark
« Reply #2 on: February 01, 2019, 10:12:46 pm »
« Last Edit: February 03, 2019, 10:42:31 pm by supriyala »