# DOTHAT Not Displaying Text **URL:** \ **Category:** Raspberry Pi\ **Created:** [September 20, 2015, 2:45pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013 "2015-09-20T14:45:42Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 2:45pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/1 "2015-09-20T14:45:42Z")
I’ve installed a DOT HAT on my Pi and while the LEDs and backlights are working perfectly, I can’t get it to display text from Python. Nothing happens when I call lcd.write(“Hello World”) nor do any of the sample programs work. I’ve tried all the suggestions here and elsewhere, have upgraded the OS to the latest version and even tried a clean re-install. I’m stuck! Some background information: it’s a brand new Pi 2, running the latest Raspian. Nothing else connected at the moment except a wifi aerial. Power supply is 2.1A which I believe is sufficient. I installed the software using the curl script and also installed WiringPi as suggested elsewhere, and made sure boot/config.txt had the spi line. Only one other thing I can think of: I have also been running a PiLite on this Raspberry Pi although I obviously don’t run both at the same time. Before I send it back as a faulty unit (I’m not sure I believe that’s the problem) have I missed anything else out? All help gratefully received! ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 5:38pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/2 "2015-09-20T17:38:57Z")
Which examples are you running, and what library are you importing to write to the LCD? Could you post a snippet of your code. ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 7:46pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/3 "2015-09-20T19:46:24Z")
Sure. I’ve tried all the examples which are supposed to display something and none of them work. Essentially it’s this: import dot3k.lcd as lcd lcd.write(“Hello world”) Nothing happens on the DOT HAT. It’s definitely working otherwise, because I can control the backlight and LEDs. ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 7:47pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/4 "2015-09-20T19:47:19Z")
Can you try: ```python import dothat.lcd as lcd lcd.write("Hello World") ``` If it works, I’ll be in the other room, kicking myself. ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 7:48pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/5 "2015-09-20T19:48:35Z")
> [@gadgetoid](#): > > import dothat.lcd as lcd Still nothing happens, I’m afraid. Don’t start kicking yourself just yet :-) ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 7:50pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/6 "2015-09-20T19:50:47Z")
Drat. Is this Python 2 or 3? I’ve go to get to the bottom of this- I’m certain there’s something amiss in the software but it’s hard to track down. ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 7:52pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/7 "2015-09-20T19:52:05Z")
$ python --version Python 2.7.3 ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 7:54pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/8 "2015-09-20T19:54:51Z")
Happy to help you track down the problem if you let me know what else to look out for. ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 7:56pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/9 "2015-09-20T19:56:32Z")
Thank you. I’ve had it happen to me once and was certain I’d fixed it. Let’s try working around the software: ```auto import dothat.lcd as lcd import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) GPIO.setup(12, GPIO.OUT) GPIO.output(12, GPIO.HIGH) time.sleep(1) lcd.write("Hello World") ``` This will no-doubt spit out some warnings, but hopefully… ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 8:00pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/10 "2015-09-20T20:00:59Z")
Nope still nothing. No warnings either though. ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 8:06pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/11 "2015-09-20T20:06:06Z")
Actually it should probably be: ```auto import RPi.GPIO as GPIO GPIO.setmode(GPIO.BCM) GPIO.setup(12, GPIO.OUT) GPIO.output(12, GPIO.HIGH) import dothat.lcd as lcd lcd.write("Hello World") ``` But also try: ```auto import RPi.GPIO as GPIO GPIO.setmode(GPIO.BCM) GPIO.setup(8, GPIO.OUT) GPIO.output(8, GPIO.HIGH) import dothat.lcd as lcd lcd.write("Hello World") ``` ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 8:08pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/12 "2015-09-20T20:08:10Z")
Still no joy. But after the statement “GPIO.setup(8, GPIO.OUT)” I get the following error: **main** :1: RuntimeWarning: This channel is already in use, continuing anyway. Use GPIO.setwarnings(False) to disable warnings. ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 8:08pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/13 "2015-09-20T20:08:41Z")
Note: I think I’m on to something with the latter. I’ve been cross referencing my library code with the schematics and think I’ve overlooked the Chip Select pin. Previously I thought the Reset pin was at fault- but reset has a 10k pullup on it. Chip Select does not! Although looking at the datasheet Chip Select is active low, so that latter code should probably be: ```auto import RPi.GPIO as GPIO GPIO.setmode(GPIO.BCM) GPIO.setup(8, GPIO.OUT) GPIO.output(8, GPIO.LOW) import dothat.lcd as lcd lcd.write("Hello World") ``` ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 8:10pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/14 "2015-09-20T20:10:43Z")
Still quiet, same warning. Here’s the full output: $ sudo python Python 2.7.3 (default, Mar 18 2014, 05:13:23) [GCC 4.6.3] on linux2 Type “help”, “copyright”, “credits” or “license” for more information. > > > import RPi.GPIO as GPIO > > > GPIO.setmode(GPIO.BCM) > > > GPIO.setup(8, GPIO.OUT) > > > **main** :1: RuntimeWarning: This channel is already in use, continuing anyway. Use GPIO.setwarnings(False) to disable warnings. > > > GPIO.output(8, GPIO.LOW) > > > > > > import dothat.lcd as lcd > > > > > > lcd.write(“Hello World”) ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 8:16pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/15 "2015-09-20T20:16:23Z")
Drat! I think we’ll have to try a replacement and retrieve yours for some testing in-house. I can’t shake the ominous feeling that I’m in for a colossal facepalm moment in the near future. Could you drop us an email to support with your order particulars, please? Thanks very much for bearing with me, I still can’t shake the feeling it’s _something_ to do with the software. It really doesn’t help that I don’t have a DOTHAT with me tonight to actually tinker with! ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 20, 2015, 8:18pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/16 "2015-09-20T20:18:14Z")
Sure, no problem. I’ll sort it out tomorrow. I’m with you - I suspect it’s a software problem too. The HAT seems to be working fine otherwise. Thanks for your help! ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 20, 2015, 8:22pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/17 "2015-09-20T20:22:21Z")
Out of curiosity, what does the soldering look like on all the pins that join the screen onto the main HAT board? I’ll upgrade you so you can post a photo if you’ve got the time! ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 22, 2015, 6:19am UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/18 "2015-09-22T06:19:03Z")
![](https://cdck-file-uploads-us1.s3.dualstack.us-west-2.amazonaws.com/flex016/uploads/pimoroni/original/1X/3a0307b7bdfef93a341c53fa104257dc2a0ee400.jpg) Ok, here’s a photo. It looks ok to me but I’m no expert! I’ll send it off today. ---
**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\ **Post date:** [September 22, 2015, 11:25am UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/19 "2015-09-22T11:25:32Z")
Looks pretty much spot on to me too! If it doesn’t miraculously work when we get it back to test ( which is some sort of law of the universe or something )- it’ll be scope time! ---
**Author:** ![nickr](https://avatars.discourse-cdn.com/v4/letter/n/dc4da7/32.png) [@nickr](https://forums.pimoroni.com/u/nickr)\ **Post date:** [September 22, 2015, 1:40pm UTC](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013/20 "2015-09-22T13:40:04Z")
Ok I will send it back to you. What should I include with the parcel? Do I need a returns number or anything or are you not that bureaucratic? [Next page](https://forums.pimoroni.com/t/dothat-not-displaying-text/1013.md?page=2)