I recently acquired the Seeed Grove Based Cape v2 which apparently does not have a populated EEPROM when delivered. According to Seed, this seems deliberate although it would be nice with a default configuration. As an answer to my inquiry regarding this, Seed referred to the EEPROM utiliity created by Josh Datko and hosted on github. While I’m prepared to try my luck with this, I’ll appreciate if anybody already equipped with this cape would be able to post a suitable image I could burn into my cape.
I hope you’ll have some answers. I have tried to read sensors (
analog, digital, I2C…) on this Cape : grove modules or not. Even the
examples ( fan module, led, 3D accelerator) on the Seeedstudio website
were not working .
Look at the comments there, and the Seeedstudio’s team answers :
https://www.seeed.cc/I-can’t-read-GPIO-from-python-in-Seeedstudio-BEAGLEBONE-Green-Wireless-t-10821.html
Question and Answers :
https://www.seeedstudio.com/Grove-Base-Cape-for-Beaglebone-v2.0-p-2644.html
It seems there is a problem on the TI chip user for the voltage transfer
http://e2e.ti.com/support/interface/voltage_level/f/391/p/497985/1814053
Faulty chip also on other systems
http://www.96boards.org/members/ldts-atsuka/forums/replies/page/2/#gsc.tab=0
This Cape (2 ex) was tested with All the « seeed » images downloaded
on the beaglebone site ( 5 at all)
Tested with 2 versions of lib Mraa … 1.0 (from the distribution) and
1.5 (from GitHub).
Python scripts with mraa.Aio(port) end with: ValueError: Invalid AIO
pin specified - do you have an ADC.. on reading any Analog port, and
others non functioning parts can be easily demonstrated.
Does anyone have a Device Tree Overlay spec that can be used for this cape? I cannot find anything like this anywhere, and clearly the cape cannot be loaded without one
I actually think it will work without anything written to the EEPROM on the cape. But I followed this technique to put something on the EEPROM and I have used it afterwards with success. I used a recent Debian on the Beagleboard:
Ensure address switches are pushed to 11 (0x57).
To obtain current contents of eeprom:
cat /sys/bus/i2c/devices/2-0057/eeprom | hexdump -C
To write to cape eeprom, first obtain the text to write:
wget https://github.com/qunanan/GBCFBBv2-Test/raw/master/eeprom.dump
Then write it to the cape eeprom:
cat eeprom.dump > /sys/bus/i2c/devices/2-0057/eeprom
When booting, capemgr will look for a firmware called BB-GREEN_GROVE-00A2 in /lib/firmware
Even though no firmware of that name is available, the cape works anyway.
Regards Peder Madsen