Forum >Gravity: Heart Rate Monitor Sensor for Arduino - Will not work on 3.3V
Gravity: Heart Rate Monitor Sensor for Arduino - Will not work on 3.3V
oda.sofie.eide 2017-11-19 07:40:20 13403 Views7 Replies Hi,
I just bought the Gravity: Heart Rate Monitor Sensor for Arduino (https://www.dfrobot.com/product-1540.html).
It works really well at 5V on my Arduino Uno, but for some reason when I change to 3.3V it seems like it does not receive any valid data. The sensor is blinking, and the green light that detects blood flow are on - but the rateValue returned when calling heartrate.getRate(); is always 0.
The product information says it should work on 3.3-6V, but that 5V is recommended. Am I doing anything wrong since it is not working at all at 3.3V?
I just bought the Gravity: Heart Rate Monitor Sensor for Arduino (https://www.dfrobot.com/product-1540.html).
It works really well at 5V on my Arduino Uno, but for some reason when I change to 3.3V it seems like it does not receive any valid data. The sensor is blinking, and the green light that detects blood flow are on - but the rateValue returned when calling heartrate.getRate(); is always 0.
The product information says it should work on 3.3-6V, but that 5V is recommended. Am I doing anything wrong since it is not working at all at 3.3V?
2021-12-31 04:55:31 kwstadinostsakalis
I found the problem in my implementation. I was delaying the execution loop by 1000ms at the end of every iteration. The example uses a delay of only 20 ms. It seems that the sensor needs to sample fast enough in order to obtain valid data. Fortunately enough this does not make any implication for my project so I have now set the delay to 100 ms (i.e. even 200ms is not fast enough).kwstadinostsakalis wrote: ↑Mon Dec 27, 2021 7:43 pmHi! I have a similar problem with this sensor. I am connecting it to a Nano 33 BLE Sense at 3.3V . When I run the example the sensor works great. When I use the same piece of code combined in a larger sketch, the sesnor fails to work properly. It has the behavior of outputing only 0 and rarely a value between 15-20 bpm. I am sure there is nothing wrong with the code logic since the code is really simple, just 2 lines of code identical with the example. Any ideas? Thank you in advance.
kwstadinostsakalis 2021-12-28 11:43:31 Hi! I have a similar problem with this sensor. I am connecting it to a Nano 33 BLE Sense at 3.3V . When I run the example the sensor works great. When I use the same piece of code combined in a larger sketch, the sesnor fails to work properly. It has the behavior of outputing only 0 and rarely a value between 15-20 bpm. I am sure there is nothing wrong with the code logic since the code is really simple, just 2 lines of code identical with the example. Any ideas? Thank you in advance. kwstadinostsakalis
kwstadinostsakalis 2021-12-17 02:21:31 The Heart Rate Monitor Sensor is a small plastic sensor that measures your pulse and other health-related metrics. Usually, the goal of this type of sensor is to simply track your heart rate. You can click here and info that person who are interested in study. Unfortunately, this sensor is not compatible with Arduino and it won't function properly with 3.3 volts. cajerid165
cajerid165 2017-11-24 01:56:46
Here is what I did, I used a firebeetle 328P, I connected the VCC to 3.3V pin of firebeetle, and other pins the same as UNO, I can get the heart rate, and do remember to set the switch to "D" robert.chen
Hi, What's the controller you usedoda.sofie.eide wrote: ↑Mon Nov 20, 2017 8:19 amI am using the hr monitor in a school project, where the sensor needs to fit in a very small size(a clock). Therefore I really need it to work at 3.3V, as I then can use the small coin cell batteries. If anyone here has experience with for example serial connecting two coin cell batteries, let me know. Google do not have a lot of answers on how to do that in a safe way :/
Here is what I did, I used a firebeetle 328P, I connected the VCC to 3.3V pin of firebeetle, and other pins the same as UNO, I can get the heart rate, and do remember to set the switch to "D"
robert.chen 2017-11-24 01:41:55 Hi, Is the red LED blink at the same speed of your heartbeat? I will do the same test on a 3.3V board robert.chen
robert.chen 2017-11-21 00:19:38 I am using the hr monitor in a school project, where the sensor needs to fit in a very small size(a clock). Therefore I really need it to work at 3.3V, as I then can use the small coin cell batteries. If anyone here has experience with for example serial connecting two coin cell batteries, let me know. Google do not have a lot of answers on how to do that in a safe way :/ oda.sofie.eide
oda.sofie.eide 2017-11-21 00:12:58 BTW, it is the SEN0203. I am using the Arduino Uno - and coding in ARDUINO IDE 1.8.5 and 1.6.8(because I was trying out a LightBlue Bean as well). I do not believe my code has anything to do with the fact that it does not work with 3V, but do work with 5V. Let me know if you do think that could be it, and I will post it immediately. oda.sofie.eide
oda.sofie.eide 