4 digit display with RP2350

[mickf]

I have been experimenting with a 4 digit Sparkfun LED display using ht16k33 and ht16k33segment 14 drivers and have successfully achieved both control of the display colon (see previous posts) and display brightness. Since the the Plasmastick2040W I was using is no longer available I am trying to make use of a Plasmastick2350W, both using micropython. The two short programmes I had written to achieve the control described above no longer function and Thonny reports various errors associated with the ht16k33 drivers. Can anyone advise me whether this is to be expected or am I doing something wrong? I loaded the “2350 with file system” uf2 file. When I look at the code for the drivers it takes me into an area of Micropython with which I am totally unfamiliar. Any help or advice gratefully received.

[alphanumeric]

A link to the drivers your trying use may help. This is above my skill level, but there are some sharp tacks here that may be able to help. :)

[bablokb]

Please also describe your physical setup, and most importantly, tell us the errors that Thonny reports.

[alphanumeric]

@mickf

display colon

Colon control with 14 segment LED displays

I am trying to use a 4 digit, 14 segment alphanumeric LED display driven from a Plasma Stick 2040W programmed in Micropython via an I2C interface. The display in question features a colon comprising two digits between the 2nd and 3rd digits. My basic problem is that I want to be able to turn this colon on and off independently from the rest of the display content. The code I have tried is:- 1 import plasma 2 from plasma import plasma2040 3 import time 4 from pimoroni_i2c import PimoroniI2C 6…

Follow on from ..."Colon control with 14 segment PED displays"

My recent post on this subject included a Micropython code snippet which I ran successfully on a Plasmestick2040W.. I find that this piece of code no longer runs and Thonny reports " can’t import name plasma2040". In desperation I have tried different .uf2 files but to no avail. Obviously I have done something to bring about this situation but have no idea what; any thoughts?

[mickf]

Hi Bablokb, I am using Thonny 5.0.0 on my MacBook Pro which is running macOS 26.2.2 and Python 3.14.3. The hardware I am using is a recently purchased Plasma2350W. Connected to this via a link cable from the QW/ST socket is a Sparkfun Qwiic 4 digit alphanumeric display. When I run the following snippet to vary the display brightness:-

2 #This script flashes the colon once every 2 seconds
3 import time
4 from pimoroni_i2c import PimoroniI2C

6 PINS_PICO_EXPLORER = {‘sda’: 4, ‘scl’: 5}

8 i2c = PimoroniI2C(**PINS_PICO_EXPLORER)

10 from ht16k33segment14 import HT16K33Segment14

12 led = HT16K33Segment14(i2c)
13 #led.set_colon(True).draw()
14 def flash_colon():

16 while True:
17 led.set_colon(True).draw()
18 time.sleep(2)
19 led.set_colon(False).draw()
20 time.sleep(2)
21 continue

23 flash_colon()

Thonny reports:-

Traceback (most recent call last):
File “”, line 12, in
File “ht16k33segment14.py”, line 62, in init
File “ht16k33.py”, line 36, in init
File “ht16k33.py”, line 139, in _power
File “ht16k33.py”, line 158, in _write_cmd
OSError: [Errno 5] EIO

Hope this helps. By the way, the uf2 file I loaded is:-

plasma_2350_w-v1.1.0-micropython.uf2

Anything else you need just ask and it may be worth repeating that this micropython programme ran successfully on the Plasmastick2040W which I used previously on the same hardware setup.

Thanks

[mickf]

Sorry Bablokb, the programme in my previous reply flashes the display colon, not control the brightness although Thonny reports the same errors in either case.

[bablokb]

You are using the wrong values for SDA/SCL. The QW/ST is on pins 20/21.

[mickf]

Thank you, Bablokb, all fixed!!! Oh to be an expert! Thanks again, hours of frustration saved.