my t4 lesson

4 posts / 0 new

Tue, 02/15/2022 - 01:02

srbp

my t4 lesson

hallo, just sharing my code as somebody can learn from my mistakes https://github.com/srbpavel/labjack_switch_board

goal: my rpi trapcam with 40Ah bateries was working ok, but with 20Ah it had some power issues. so it was right time to buy T4 and start using it.

with labjact doc's and techexploration course i have build small app to measure my batteries, backup to csv, publish to db and start the analyze.

the code is not perfect, but it does the job at the moment
i also use if for temperature monitoring with ds18b20 (at the moment i can measure 3x sensors per bus/pin. unfortunatelly i did not succeeded to have 5+sensors per bus.
few months ago i stop tweaking it, as now more focused on rust lang.

enjoy, pavel

Mon, 02/21/2022 - 01:31

srbp

please, can you share with me

please, can you share with me what was the maximum number of one_wire sensors you have connected to single pin?

as i believe there will come time, when i will need to update my app as more sensors will be needed.

thank you, pavel

Mon, 02/21/2022 - 15:18

soloman

We previously had success

We previously had success with around 5 sensors on one pin, but this was with a breadboard and short cables, so cable length could effect the feasibility. Unfortunately, I do not believe we have done any testing beyond that.

We would recommend you avoid using the FIO terminals for 1-wire. The FIO have a bigger series resistor on the outputs than the EIO/CIO/MIO, so you could see worse filtering effects and voltage droop on the FIO.

Tue, 02/22/2022 - 04:52

srbp

thank you soloman

- 5 is ok for me, as i can use more pins [was just wondering and want to be sure i implemented rom search cycle correct way]

- i know about the FIO as mentioned in your doc

pavel