SparkFun Forums

[GDSever]

Can you all think of any reason why the FTDI Basic wouldn't communicate with the 4D uLCD?

When I try to download a demo program to the display (a free day purchase), the GFX development environment tells me that "Device is not responding. Please check your configuration. Have you got an SGC PmmC loaded by mistake?".

I didn't reflash the firmware, so it is still GFX - and the display shows as much when it first boots, but for whatever reason I can't get the 4D Workshop app to find the display. I've double-checked the connections several times - two pins grounded on the display, tied to the power GND and FTDI Basic GND, the RX/TX lines cross appropriately (RX on FTDI Basic runs to the display TX, and vice-versa)...

Help is greatly appreciated! I'm walking away after an hour of messing with it to see if something comes to me...

I admit I am a complete novice when it comes to these displays, and was hoping my knowledge with other platforms would make this learning curve relatively simple, but I've been shut down right out of the gate!

[Sacman]

You might want to verify that you have the latest pmmc. The latest one is R20 for the Goldelox displays.

4D Systems is constantly upgrading these. It is possible that the ones from SFE have been there for a while. If you are using the latest version of the IDE, this could be causing a conflict and it doesn't cost you anything to load a new one.
I have a 144 and a 28PT and have no problem when using the USB to UART converter sold by 4D Systems.

You also might want to visit the 4D Systems forums. They are very helpful over there.

Luck,

Wade

[GDSever]

If you are using the latest version of the IDE, this could be causing a conflict and it doesn't cost you anything to load a new one.

When I boot it indicates v2.0 on the display - and I don't have their standard hardware for reprogramming - I was hoping to do it with the FTDI Basic - but if I have to buy the 4D PmmC programmer hardware, I suppose that's OK (aside from the US$15 for shipping).

[Sacman]

The FTDI should work. The ones sold by 4D Systems are just UART to USB bridges.

You may be missing the reset. You say you have two pins tied to ground. One of those, the DTR pin needs to be released from ground to program. In other words, using the 4DGL UART bridge, there is a DTR pin that is tied to the RES pin on the display. It sends a ground to that pin to reset the module but then it is released.

So try the following:

1) Connect the display to your USB-Serial setup with Power
2) Short the RESET to GND
3) Click the download button (either PmmC-Loader or Workshop Downloader)
4) Release the the RESET from GND

This is straight out of the forums.

One other simple thing to check, when the 4DGL IDE sees the module, the little dot next to the port selection should be blue.

Luck,

Wade

[GDSever]

Wade, thanks for the guidance - I'll give this a try tonight. I ordered one of the 4D Systems bridges in desperation on Saturday (thru Saelig.com), but I always am interested in knowing what my alternatives are, so I'll have to try the FTDI Basic one again using your steps .

Best regards,
-Garrett

[Sacman]

Awesome.

I have the 4D Systems one and I have had a few problems with it not resetting the module as well. Also, I tried to program it last night with the Receive pin disconnected and it gave me an error. I think it was the same error you are getting so you might want to check that wiring one more time.

These displays are great. At first I was a little put off by the cost but ultimately the Goldelox and Picasso chips make it worth it. The greatly simplify the code needed. The only drawbacks I could point to is the low speed uSD access (which is onboard) and the lack of a back buffer for flipping screens.It redraws to the screen every cycle instead of drawing to a buffer and flipping.

I have spent the last couple of days working out how to send and receive serial data to it from a PIC. I am still using the 4DGL version since it is much easier to handle the display functions that way and I need to use the Touch Image Function on my 2.8" LCD which does not work the same through the SGC mode.

My thumb joystick from Sparkfun with breakout board arrived today at work. I ship everything there so my wife doesn't know how much I spend. I can't wait to get there and start drawing on the screen. This isn't my ultimate goal but it will be fun to do. Tomorrow I get my stepper motor. Then things really start to get interesting.

Wade

[GDSever]

Wade, you totally nailed it. It was the reset piece that I was missing. It took a try or two before I was able to get the module to accept the download (was purely a timing issue), and then it worked great.

Thanks so much for the tip! I signed up over at the 4D forums, so maybe I'll see you over there sometime.

[GDSever]

As a follow-up, I realized my FTDI basic has a DTR pin on it - wiring that to the RESET pin on the display took care of everything - so the FTDI Basic works perfectly as a bridge device. I might have to work up a Fritzing diagram or something to post somewhere...

Thanks again for the great info!