# Plasma 2350 current sensing
**URL:** https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294
**Category:** New Products
**Created:** [August 16, 2024, 10:38am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294 "2024-08-16T10:38:23Z")
**Posts on this page:** 18
**Page:** 1
### Author:  [@rde1](https://forums.pimoroni.com/u/rde1)
#### Post date: [August 16, 2024, 10:38am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/1 "2024-08-16T10:38:23Z")
Does the Plasma 2350 include low side current sensing (accessible via ADC3) as on the original Plasma 2040? I use the current value to dynamically determine the number of LEDs that are attached.
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### Author:  [@dBerriff](https://forums.pimoroni.com/u/dBerriff)
#### Post date: [August 18, 2024, 8:35am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/2 "2024-08-18T08:35:14Z")
A quick test suggests, unfortunately, no. I have tried ADC3 GP29 and there is no significant variation (u16 in range 7 665 to 7 681) as I modulate the output of an 8 x 8 WS2812 pixels grid. I will try with a strip of 300 pixels next. [Edit: same result.]
I would really like to see the schematic. There is also no mention of logic level-shifting to 5V either. While I have not found this to be essential in the installations I have tested (R Pi Pico 1 controlling up to 300 pixels), it gave an extra bit of operational confidence with the Plasma 2040. Adafruit recommends using a level-shift to 5V for the DAT signal.
The Plasma 2350 is still very convenient for quick installs and testing, and I will continue to use it.
Is there any other test you would like me to try?
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### Author:  [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)
#### Post date: [August 18, 2024, 12:22pm UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/3 "2024-08-18T12:22:51Z")
Have a look at the bottom of the pinout. It shows 5V data and 5V Clock. It is using logic level shifting to +5V.
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### Author:  [@dBerriff](https://forums.pimoroni.com/u/dBerriff)
#### Post date: [August 18, 2024, 1:07pm UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/4 "2024-08-18T13:07:54Z")
Thank you - I missed that at a smaller scaling. Good to know. đ
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### Author:  [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)
#### Post date: [August 18, 2024, 3:11pm UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/5 "2024-08-18T15:11:09Z")
No problem, I miss stuff like that quite often.
I have the shop page set to render as large as possible, to make things easy on these old eyes. ;)
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### Author:  [@rde1](https://forums.pimoroni.com/u/rde1)
#### Post date: [August 19, 2024, 6:42am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/6 "2024-08-19T06:42:16Z")
Thanks for testing this. Seems a pity they dropped the current sensor, it was a nice way to count leds. Would be good to see the schematic or get an official response from Pimoroni.
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### Author:  [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)
#### Post date: [August 19, 2024, 6:56am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/7 "2024-08-19T06:56:28Z")
Just my observation.
The Plasma 2040 has current sensing.
The Plasma 2040 W âStickâ doesnât have it.
The Plasma 2350 is the same form factor as the 2040 Stick.
Lack of space on the Stick format?
Keeping the cost down?
It is a bit of extra parts to add / fit on the board.
And R12 needs to be able to handle the current without getting too hot in the process. I would think itâs going to be large and chunky.
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### Author:  [@hel](https://forums.pimoroni.com/u/hel)
#### Post date: [August 19, 2024, 9:11am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/8 "2024-08-19T09:11:32Z")
Yep, Plasma 2350 doesnât have current sensing as we took the opportunity to reduce the complexity (and cost) for the stick-sized version. Nice to hear that you use this functionality though ~~@dBerriff~~ @rde1 - we got the impression that it wasnât very widely used.
We might bring it back in the future on a bigger, more fully featured Plasma board, if one of those happened to be in the pipeline đ
RP2350 board schematics will be forthcoming soon, waiting for engineers to return from their summer hols :)
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### Author:  [@rde1](https://forums.pimoroni.com/u/rde1)
#### Post date: [August 19, 2024, 9:34am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/9 "2024-08-19T09:34:25Z")
Actually is me @rde1 using this. I send a single white value along the led strip and wait for the current to drop - allows counting of the LEDs. The current value is accurate enough for at least 120 LEDS.
I wanted to control the LEDs colours etc via wifi so I made this setup where there is a Pico W connected to the Plasma 2040 via i2c:
> **[PXL\_20240819\_092942001.jpg](https://drive.google.com/file/d/1quARAAZ3pcmxdqyO2MO1v0OEUsaHPs3Q/view?usp=sharing)**
>
> Google Drive file.
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### Author:  [@hel](https://forums.pimoroni.com/u/hel)
#### Post date: [August 19, 2024, 10:55am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/10 "2024-08-19T10:55:26Z")
Oops, apologies - going too fast.
Thatâs very clever!
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### Author:  [@bablokb](https://forums.pimoroni.com/u/bablokb)
#### Post date: [August 19, 2024, 12:55pm UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/11 "2024-08-19T12:55:21Z")
> [@rde1](#):
>
> I wanted to control the LEDs colours etc via wifi so I made this setup where there is a Pico W connected to the Plasma 2040 via i2c
One thing improved on the Plasma2350: it now exposes UART. So you can control the Plasma2350 and have I2C.
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### Author:  [@rde1](https://forums.pimoroni.com/u/rde1)
#### Post date: [August 19, 2024, 2:42pm UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/12 "2024-08-19T14:42:08Z")
I thought there was no UART on the Plasma 2040 ⌠then I looked at the rp2040 datasheet and it shows GP20 and 21 available for UART 1. Not shown on the familiar pin out pictures for some reason.
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### Author:  [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)
#### Post date: [August 19, 2024, 8:20pm UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/13 "2024-08-19T20:20:52Z")
They are shown here, [Raspberry Pi Pico GPIO Pinout](https://pico.pinout.xyz/) for the Pico 2040.
I do believe they are preconfigured for i2c on the Plasma 2040. Thatâs the intended use anyway. As is shown on the schematic.
[plasma2040.sch (shopify.com)](https://cdn.shopify.com/s/files/1/0174/1800/files/plasma2040_schematic.pdf?v=1629994431)
You wonât know if thatâs an issue until you try to repurpose them software wise.
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### Author:  [@dBerriff](https://forums.pimoroni.com/u/dBerriff)
#### Post date: [August 23, 2024, 7:17am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/14 "2024-08-23T07:17:40Z")
Whatever is available on the Pico 1 for a given PIO pin is available on the Plasma 2040 for the pins that it makes accessible. The RP2040 (or 2350) chip determines what is available on a GPIO pin, not the board. A pin cannot be âpreconfiguredâ unless it is a debug, voltage or ground pin. Everything else is setup by software.
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### Author:  [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)
#### Post date: [August 23, 2024, 8:14am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/15 "2024-08-23T08:14:57Z")
Preconfigured by software, is what I meant to convey. I got lazy in my reply. Sorry about that. :(
The library / module for the Plasma 2040 âmay possiblyâ set them up for use as shown by the board lettering. Iâll be honest and say that a lot of what goes on in the background, Micro Python wise is a mystery to me. Even more so C, which is what a lot of Pimoroniâs Micro Python code is based on / originated from.
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### Author:  [@rde1](https://forums.pimoroni.com/u/rde1)
#### Post date: [August 23, 2024, 9:31am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/16 "2024-08-23T09:31:41Z")
Yes ⌠but for some reason the âofficialâ pinout diagram at:
[https://www.raspberrypi.com/documentation/microcontrollers/images/pico-2-r4-pinout.svg](https://www.raspberrypi.com/documentation/microcontrollers/images/pico-2-r4-pinout.svg)
does not show 20 and 21 as UART. This is the image in the original Pico book also.
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### Author:  [@dBerriff](https://forums.pimoroni.com/u/dBerriff)
#### Post date: [August 23, 2024, 11:00am UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/17 "2024-08-23T11:00:52Z")
The diagram only shows hardware options and you cannot connect the chip UART hardware to GPIO pins 20 and 21. As these pins are connected to the QT socket, I believe the intention is that you can hook up I2C peripherals. I will attach an LCD panel.
See the UART reference here:
[https://docs.micropython.org/en/latest/rp2/quickref.html](https://docs.micropython.org/en/latest/rp2/quickref.html)
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### Author:  [@rde1](https://forums.pimoroni.com/u/rde1)
#### Post date: [August 27, 2024, 2:49pm UTC](https://forums.pimoroni.com/t/plasma-2350-current-sensing/25294/18 "2024-08-27T14:49:11Z")
Just one more thing ⌠if you happen to make any new âPicoXX on boardâ products, _please_ expose the SWD pins! I tend to use C++ and rely on the pins for quick code upload.
Lack of SWD has put me off buying many of your great PicoW on board products.