3.3v pins - Printable Version +- OpenMarine (https://forum.openmarine.net) +-- Forum: OpenPlotter (https://forum.openmarine.net/forumdisplay.php?fid=1) +--- Forum: How do I...? (https://forum.openmarine.net/forumdisplay.php?fid=3) +--- Thread: 3.3v pins (/showthread.php?tid=3509) |
3.3v pins - Lazzz - 2021-06-18 I am using both 3.3v GPIO pins on my Pi4 - 1 with BMP280 sensor & the other (17) with DS18B20 temp sensors. I need to use another relay on a 3.3v pin. Is it possible to double up the BMP180 & the DS18B20 sensors on one pin?? Is there any other way I can use this new relay or do I get rid of the BMP280?? Both 5v pins are being used as well. TIA RE: 3.3v pins - SCarns - 2021-06-18 how about something like this? https://www.amazon.com/GeeekPi-Connectors-Raspberry-Expansion-Compatible/dp/B08C2DJBT2/ref=sr_1_4?dchild=1&keywords=raspberry+pi+gpio+double+connector&qid=1623996440&sr=8-4 RE: 3.3v pins - PaddyB - 2021-06-18 Pins 1 & 17 are already joined internally so should be no problem sharing externally. Think 500mA available apart from early models. RE: 3.3v pins - burgoynebc@netscape.net - 2021-06-18 I'd be interested in hearing how you make out with the dallas sensors. I setup about 10 on one wire with pullup resistors etc. I got good results with single units but when multiple units were wired in, I got sensors that would not read over ?135F. I never could figure out why and gave up on them Richard SV Zolanda RE: 3.3v pins - Techstyle - 2021-06-18 (2021-06-18, 07:58 AM)burgoynebc@netscape.net Wrote: I'd be interested in hearing how you make out with the dallas sensors. I setup about 10 on one wire with pullup resistors etc. I got good results with single units but when multiple units were wired in, I got sensors that would not read over ?135F. I never could figure out why and gave up on them I have 5 attached, but only 4 seem to show up. somebody on the Signal K slack channel said that you get much better results with real Dallas semiconductor made sensors, rather than the nice looking generic packaged ones you find on Amazon. I have some of both but only have the Amazon ones fitted at the moment. I am thinking about swapping over and seeing if that is true RE: 3.3v pins - holgerw - 2021-06-18 use an relay here , no, never" but for signaling the level to some transistors in between - you may use lots of relays, but not directly! the 3.3 Voltage is only for signaling - never use it for power delivering, it only an little poor chip there. realys need an amplifie aka transistor and mostly use 12 v to react. try an little googleing on interfaces for relays. holgefr RE: 3.3v pins - Lazzz - 2021-06-19 (2021-06-18, 11:43 PM)holgerw Wrote: use an relay here , no, never" but for signaling the level to some transistors in between - you may use lots of relays, but not directly! the 3.3 Voltage is only for signaling - never use it for power delivering, it only an little poor chip there. realys need an amplifie aka transistor and mostly use 12 v to react. This is what I want to use - the 3.3v is only for signaling: 5V Single Channel Relay Module 10A Australia (core-electronics.com.au) Controlling a Solenoid with Raspberry Pi and a Relay - Tutorial Australia (core-electronics.com.au) I have 5 DS18B20 sensors running all accurate with no problems. Thanks for your help everyone RE: 3.3v pins - holgerw - 2021-06-19 (2021-06-19, 12:10 AM)Lazzz Wrote: This is what I want to use - the 3.3v is only for signaling: 5V Single Channel Relay Module 10A Australia (core-electronics.com.au) They should be okay, can even work with 3.3 Volt from the pi. For the Guy with 10 or more OneWire-Sensors, first try for me is to go down with the PullUp-Resistor, this should replaced with 2k2 or even 1k Ohms. |