I just received my Panda Touch screen for the P1s and love it! But I noticed that there is a 4-pin connector next to the power switch labelled “12C”. The manual shows this as a “12C interface: Connect temperature/ humidity sensors, etc.”. But I could find no such sensor for sale on their website.
Does anyone know how this connector might be used? Is there a sensor available for purchase that will fit it?
It’s for future expansion. There isn’t a sensor available yet and the firmware doesn’t currently support it.
The I2C protocol is a serial interface that is supported by a wide variety of microcontrollers. Panda Touch clearly has future aspirations. However, that doesn’t mean you can experiment to see if those features are in fact active and just not advertised yet. They may not appear unless the code is looking for a sensor. The good news is that the sensors are so darn cheap that you can’t just buy one. Here’s an Amazon link with numerous choices
https://www.amazon.com/s?k=i2c+temperature+and+humidity+sensors
Just go with any sensor that advertises AHT10 compatibility and it should work. The AHT21 is the newer version but it only has a difference of 85 vs 80c temperature improvement over the AHT10. Since you’re just trying to test it out, go cheap.
Go with a kit that already has the four wires included, otherwise you’ll want to get dupont connector jumper wires to hook it up. SDA, SCL, GND and VDC on the Panda they are noted like this:
Don’t be intimidated by I2C, it’s one of the most hacker friendly interfaces right up there with RS232 and USB-A. It’s very difficult to cause any damage unless you wire an external power source to it. The sensors gain their power form the Panda itself, that’s how I2C designed.
Worse comes to worst, your Panda will ignore it or just won’t boot up correctly. Power it off and disconnect the sensor and return the sensors to Amazon and get your $6-$10 back.
I tried but the firmware seems not ready for it yet, i was just ignored
Post a link of the sensor you tried so others will benefit from your experience.
These 2:
https://www.aliexpress.com/item/1005006194903568.html
https://www.aliexpress.com/item/1005004090641530.html (the black one)
I wonder why if BTT wanted to use the feature, they would not have designed a pogo switch with multiple prongs. Connecting a plug behind it defeat the design objective of being able to take the panda touch off the dock and use it remotely. It seems to me the ESP32 screen they procured had these inputs available and they just installed a connector behind just in case not really thinking about what to do with it. The connector should be on the dock, not the screen…
Thanks for sharing. I wouldn’t call your test conclusive, though. Both of those have the BME280 barometric sensor. What that means is that they are not sending the same signals as the raw AHT10 protocol would. I haven’t looked at the datasheet for the BME820, but I’m willing to wager that if it’s like many of the other I2C sensors I’ve played with, the data stream is probably sending more data than just temperature and humidity. If the Panda code isn’t expecting that, then it would be logical that it would just ignore the stream. What’s more, most ARM code has a test loop in the library to not instantiate the code unless a valid sensor is present. This allows for tighter code and better error checking.
The ESP32 that runs the Panda Touch isn’t ARM based, it’s a Tensilica Xtensa 32-bit LX6 processor with its own architecture.
Duly noted but the I2C implementations are identical over architectures with minor differences in the dev environment. I2C is the great equalizer among SOCs. It’s a beautiful thing.
Thanks for all the info. I just placed an order for 2 of the AHT21 12C modules. Based on what everyone is saying, it probably won’t work, but they’re cheap so what the heck.
Yeah, the connector location seemed odd to me too. Like you say, should be on the dock. But I plan to have mine mounted to the printer anyway so it’s not much of an issue. The included mounting bracket puts it in the way of removing the printer top when a riser is installed so I’ll probably print a bracket that will swing out from the side of the printer.
I printed this one, I found it to be the nicest idea for the panda touch
This is making wanting to get the Panda Touch.
Thanks for the link, philch. The Panda touch already comes with a dock that mounts in a similar position, but doesn’t block the original screen.
I have an AMS riser that lets me slide the glass top off of the printer, and reinsert it into a shelf in the riser. But to glass top needs to slide out of a small area at the front of the riser, and these kinds of docks block that.
So I’m looking into creating something that would let me mount the Panda Touch on the side of the printer, completely out of the way of the riser.
I sent a note to BIQU asking about the 12C connector, if it was supported in the firmware, and where the temp/humidity would be displayed. They replied: “I2C port for temperature/humidity sensors supported in future firmware etc. The current firmware is not supported yet, and the firmware that can be used has not been uploaded yet. The displayed location is on the homepage, with icons.”
So it sounds like firmware support might be in the next release. There is an icon on the home screen that currently says “N/A”, so I’m guessing that’s where the temperature and/or humidity will be displayed. Probably designed for monitoring the chamber.
Try The ultimate Panda Touch dock V2.0 for Bambulab P1 series by gerdjentz - MakerWorld
i have a riser that does what yours does, glass slides out to reposition. With that mount it’s slimmer than most, and you ca easily remove the PT to slide the glass.
I asked about this on the GitHub repository in Feburary with the reply that it is not yet implemented.
This may be a reach, but maybe it’s for connecting with sensors on a Panda hotend upgrade, either the Panda Revo or maybe something more advanced than that which is still in development? Look at their competitor’s more advanced hotend, the Duet3D Revo Roto, which has two temperature sensors, an accelerometer, and a fancy pants RF z-probe: Duet 3 Roto Toolboard - CAN-FD expansion for E3D extruder Revo Roto
Hey there. I am with BTT. Currently the sensor is not implemented but it will be coming in V1.0.4 which is slated for release in about 8 weeks. V1.0.3 is releasing for public beta next week.
Hi looxonlie. It’s great to get a reply from a BTT person - thanks! Are you able to tell us if the connector will work with any 12C humidity/temp sensor for general use? Or is the firmware only going to support a specific use for that port?