FWIW, I am not also getting text to display on JHD1313M1 (the v2 version of the LCD). I'm using Johnny-five. I tried multiple variations of https://github.com/rwaldron/johnny-five/blob/master/eg/grove-lcd-i2c.js and just like above, I can change the background but I cannot display text. If you happened to resolve this issue, please post your solution. Otherwise, I'll wait for someone's response with bated breath.
EDIT: I forgot to mention my env.
I'm using an Edison on an Arduino BB w/ a Grove RGB LCD on a Grove base shield.
Alright. I figured it out. Actually, someone else figured it out and I read their post online. The Arduino BB and Grove BS have to be set to 5v. I had the base shield at 3v. Once I flipped the switch, it worked. Hope that works for you flux2002.
I did see similar article on voltage. This was one thing a triple checked with voltmeter before posting. Unfortunately even after ensuring 5V selected on BS and measuring 5V at LCD, still no text, only RGB backlight. I would like to know what was changed between v2.0 and v3.0 Grove LCD as wondering if any changes could cause this issue with posted code/addresses in original posting.
If you are still interested, you could try the following example code:
You can compile the code above with the command:
g++ -o lcd lcd.cxx -I /usr/include/upm/ -lupm-i2clcd
Before doing so, you should install MRAA. In order to do so type the following:
echo "src mraa-upm http://iotdk.intel.com/repos/1.5/intelgalactic-dev" > /etc/opkg/mraa-upm.conf opkg update opkg install libmraa0
If you don’t have any more repos configured do: opkg upgrade. Don't do this if you have AlexT's repo configured, if you do so, you'll be left out without any space in your board.
Peter, this ultimately worked, thanks! I first ran opkg update with src mraa-upm. and ran sample program, but text still did not display. I then ran opkg upgrade and ran sample program, "Hello World" and text then displayed. I am using Intel's 2.1 Yocto image and Intel repos, but thank you for note on AlexT.
Great to hear that it worked . If you ever encounter any other issue, don't hesitate to come back to the community.