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User avatar
By bowen
#209178
Hi there,
I have two sparkfun products:
1. Openscale : https://www.sparkfun.com/products/13261
2. Blynk board: https://www.sparkfun.com/products/14682

I am trying to connect these two.

From this blog:
https://learn.sparkfun.com/tutorials/openscale-applications-and-hookup-guide#resources-and-going-further

It says the "In the bee scale application , OpenScale is hooked up to Blynk Board and the data collected is pushed to a data-streaming services."

However I cannot find anywhere how OpenScale can hook up to blynk board:
https://makezine.com/projects/bees-sensors-monitor-hive-health/

Can anyone give me any advices?

I am a professional Programmer woking in IT industrial, however I am not familiar with chip connections.
Any help will be much appreciated!
User avatar
By TS-Chris
#209199
Hi bowen

That looks like a typo in our guide. The beehive project used a Particle Photon rather than a Blynk Board. I believe the Photon was connected to the Blynk server though for it's data collection. I can't verify this since the beehive isn't actually in place anymore and the person that created the project is on an extended vacation right now.

The OpenScale communicates via TTL serial so you'd need to connect the OpenScales GND, RX and TX pads to GND TX and RX on the Blynk Board. (or Photon if you're using that) The rest of the work would be done in software.
User avatar
By TS-Mark
#209201
Also, one quick note about connecting the OpenScale to the Blynk board. The Photon has 5V tolerant digital pins so you can get away with connecting the serial header on the OpenScale to the Photon BUT the ESP8266 on the Blynk board runs at 3.3V and is not 5V tolerant so you will need to use a logic-level converter like this Bi-Directional Logic Level Converter to shift from 5V to 3.3V and vice versa. If you are not familiar with logic levels in electronics, I would recommend reading through this tutorial.
User avatar
By bowen
#209318
TS-Mark wrote: Fri Nov 01, 2019 2:41 pm Also, one quick note about connecting the OpenScale to the Blynk board. The Photon has 5V tolerant digital pins so you can get away with connecting the serial header on the OpenScale to the Photon BUT the ESP8266 on the Blynk board runs at 3.3V and is not 5V tolerant so you will need to use a logic-level converter like this Bi-Directional Logic Level Converter to shift from 5V to 3.3V and vice versa. If you are not familiar with logic levels in electronics, I would recommend reading through this tutorial.
Hi TS-Mark,
Thanks for your information about voltage.

However I found the Photon also documented as 3.3v:
https://docs.particle.io/datasheets/wi-fi/photon-datasheet/
https://core-electronics.com.au/particle-photon.html

Do you mean Photon can actually tolerant 5v regardless what it states in the datasheets?

Cheers!
User avatar
By TS-Mark
#209324
Hi again bowen,

The Photon does run at 3.3V but the digital I/O pins are 5V tolerant. The table here lists the ratings for the GPIO and peripheral pins and anything labeled FT, per the note below the table, is 5V tolerant with a few minor issues outlined in that note.