Thanks, I’ll look into a 10kg one
Did you end up going back to the adc setting or sticking with the esp32_touch setting?
Dear florianmulatz,
Thanks to share the schematics, what a pity that is not in easyeda format, I tried to import to easyeda but not works… If anyone can create in easyeda format…
Thanks,
Off topic but how did you make this card?
The card is included in the first post.
Hi, getting back to this since I also couldn’t find the resistance out of bed last time
Am I doing this right?
I hooked up a R1 =100k resistor (2 units of 50k in series), V1= 2.66V (out of bed), V2= 2.42 (bed occupied).
Getting R2 = 1,052,174 ohm (from the voltage divide calculator)
Using SQRT(R_in_bed*R_out_bed)=R1 gives me 324,372 ohm.
My V1 isn’t 3.3v because I’m probably not using the correct resistor values yet?
Hi, am I doing this right? Combine both 60cm sensor.
Currently have 1 fsr strip connected to an esp32 on my right side of the bed and it’s working correctly.
Combined 2 fsr like this and added to my left side of the bed, but now I’m getting wrong values for both sides (less than 0.5v when the bed’s not occupied).
Still figuring out if it’s wiring issues or something else
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hey mate I also did this, but I am having trouble with my automations/detections I feel like I need to debounce the sensor\input boolean that triggers when the bed is considered “occupied”
How did you set yours up?
To avoid soldering, these pluggable screw terminals work well with the force sensitive resistor ends. https://www.amazon.com/dp/B0BZP9922W
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This worked brilliantly! Thank you so so much for an amazing guide for my first esphome/esp32/circuitry project. I am a complete novice with 0 skills related to soldering, electrical circuits etc. I had to review what voltage, current, resistance was, how to use a multimeter, how circuits work. Lot of high school physics eventually came back to me 
I spent some time first getting things working with Arduino IDE and a breadboard. I used some sample code found online first. After reliably understanding the voltage divider circuit and little bit of math involved, everything was so easy after that.
All in all took me 4 hours on a Friday evening + Saturday morning
Soldered FSR ends to some jumper cables (hard skill but easy after some practice)
Taped FSR to bed slat
Measured R1 w multimeter
Installed ESPhome and configured as in the post
Connected to breadboard using resistor w calculated R1
Set up input number helper in HA
Profit
All that is left for me is to now abort this breadboard and get something more durable with a housing.
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Did you find a solution to this?
Nah, i just used another esp for it.
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I’ve just bought the SF15-600 as well and found the datasheet here: SF15-600@10KG - LEANSTAR | X-ON Electronics
After some translation, I found out that without pressure this FSR should have resistance above 10M.
From the datasheet:
采用分压方式测量。将不同大小的压力施加于传感器上产生的电阻值的变化，转换为电压的变化，Vout为输出电压，可接到后端电路。 根据实际情况选择R1，通常可取47k Ω~1 MΩ； 无压力时，传感器阻值在10 MΩ以上，等效于断路。
which apparently translates to:
Measured using partial pressure method. The change in resistance value produced by applying different amounts of pressure to the sensor is converted into a change in voltage. Vout is the output voltage, which can be connected to the back-end circuit. Select R1 according to the actual situation, usually 47k Ω~1 MΩ; When there is no pressure, the sensor resistance is above 10 MΩ, which is equivalent to an open circuit.
Unfortunately my bed doesn’t have any good hard surface to mount it on so I tried it between two soft mattress but the resistance for me is all over the place. My multimeter can apparently measure up to 60M Ohm but even with that the FSR was out of range when I was out of bed.
I might try to use the heat gun method to see if there will be any difference.
You can use a wooden slat before trying to heat
Already tried, it would have to be really thin piece of wood to not notice it but it I believe it would eventually break. With a wooden slat it was very noticeable.
It did work for the most part but when I laid down on my belly, it barely registered so I’ll have to figure out something for that as well.
If you have a mattress protector it might work between that and the top mattress. But yeah this method does rely on having a firm surface to mount the FSR.
Trying it out currently too with the same wiring and it doesn’t work for me as well. This was the only one I could replicate as I have no idea about all the schemas posted here.
Could anyone point us in the right direction as to why it doesn’t work?
The truth is that I’ve been able to make it work since then.
It turns out that my mistake was not soldering the header. I thought it also works without. Noob’s mistake. After that it worked for me and since then I have progressed to the ESP32 board and it also works.
Feel free to share yours and we’ll see if there’s a mistake somewhere.
Sorry, can you please explain what you mean by soldering the header based on the pictures you’ve provided in your earlier post?
I’ve tried the exact breaboard layout you’ve posted and tested it without any bed. Just plugged in to see if I get any readings with different resistors. I have something like this (posted in this thread) so I still need to figure out the values for the provided formular
That’s why I wanted to try it out without anything first to see if I can even get it to work
Edit: Maybe my bed is not so fitting for this… I just tried to measure the resistance for the FSR sensor by strapping it on one of the slats above the middle on one of the sides. With just my mattress on top I get no reading at all with the meter staying at 1. When I’m just lying on the mattress I don’t get anything too, only when I sit on the part the sensor is under.
Not sure how to proceed from here