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by tlfong01
Thu Jan 24, 2019 6:56 am
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4257

Re: Cat Home DIY Q&A - Solenoid MCP23017 How To

... (DBS0180 notes) https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&start=375#p1357003 (I2C Extender P82B715) https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&start=375#p1362527 (Detecting 8 MCP23017) https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&start=400#p1367365 ...
by tlfong01
Wed Dec 05, 2018 12:21 pm
Forum: Automation, sensing and robotics
Topic: Reading old weight scale
Replies: 124
Views: 30253

Re: Reading old weight scale

... https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&hilit=DS3231&start=300#p1351680 I2C Bus Extender P82B715 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&hilit=DS3231&start=300#p1351545 I2C Baud rate setting https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&hilit=DS3231&start=300#p1351737 ...
by tlfong01
Mon Sep 10, 2018 3:02 am
Forum: Python
Topic: GPIO.input voltage levels vs edge detection
Replies: 430
Views: 96572

Re: GPIO.input voltage levels vs edge detection

... a breadout board for USD10. I could not find any cheaper version in AliExpress or TaoBao. So I will not try it now. You recommended I2C extender P82B715 is already very good, for my I2C circuits with too many I2C devices. I2C Bus Multiplier The other I2C toy I might try later is the following: ...
by tlfong01
Fri Sep 07, 2018 9:18 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

tlfong01 wrote:
Thu Sep 06, 2018 2:28 pm
Now the greedy hobbist has 7 MCP23017s or
16 x 7 = 112 GPIO pins!

P82B715 I2C Bus Extender Testing Notes

Now the greedy guy has connected 8 MCP23017s to get 16 x 8 = 128 GPIO pins!
by tlfong01
Thu Sep 06, 2018 2:28 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

5. The three outputs of P82B715 becomes double extended 5V I2C #1, #2, #3. 6. 5V I2C #1 connects to 4 MCP23017, #2, #3 each connects to 1 MCP23017. Next is to connect more I2C devices to the double extended bus channels and see how many ...
by tlfong01
Thu Sep 06, 2018 1:34 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

5. The three outputs of P82B715 becomes double extended 5V I2C #1, #2, #3. 6. 5V I2C #1 connects to 4 MCP23017, #2, #3 each connects to 1 MCP23017. P82B715 I2C Bus Extender Testing Notes Next is to connect more I2C devices to the double ...
by tlfong01
Thu Sep 06, 2018 1:17 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

Now I am a rich guy with 6 x 16 = 96 gpio pins! :) [/quote] P82B715 I2C Bus Extender Testing Notes Now I have assembled the following and tested OK. 1. Rpi3B+ I2C (SCL, DSA, Gnd) connects to signal routing board (SRB). 2. SRB I2C connects to input of ...
by tlfong01
Wed Sep 05, 2018 2:47 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

tlfong01 wrote:
Wed Sep 05, 2018 2:22 pm
I have successfully connected 6 MCP23017 to the I2C bus.
Now I am a rich guy with 6 x 16 = 96 gpio pins! :)

P82B715 I2C Bus Extender Testing Notes
by tlfong01
Wed Sep 05, 2018 2:22 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

tlfong01 wrote:
Wed Sep 05, 2018 3:22 am
Faulty TXS0102 replaced. All 4 of them OK now.

P82B715 I2C Bus Extender Testing Notes

I have successfully connected 6 MCP23017 to the I2C bus.

Now I am a rich guy with 6 x 16 = 96 gpio pins! :)
by tlfong01
Wed Sep 05, 2018 3:22 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

First test of P82B715 is good. I found 1 of the 4 level shifter (CJMCU 0102 = TXS0102) is not working, and 1 of the 4 MCP23017, the original one, is unstable. I need to swap both to prove that they are indeed bad guys. P82B715 I2C ...
by tlfong01
Tue Sep 04, 2018 2:18 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

Quad I2C Level Shifter x 4 is now manually selected all. P82B715 I2C Bus Extender Testing Notes First test of P82B715 is good. I found 1 of the 4 level shifter (CJMCU 0102 = TXS0102) is not working, and 1 of the 4 MCP23017, the original one, is unstable. ...
by tlfong01
Tue Sep 04, 2018 8:55 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

Quad I2C Level Shifter x 4 is now manually selected all. P82B715 I2C Bus Extender Testing Notes Now I am connecting the following to the four demux 5V I2C channels: IOX MCP23017 x 4 RTC DS3231 ADCDAC PCF8591 [/i][/color] This is where I got stuck last ...
by tlfong01
Tue Sep 04, 2018 8:00 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

tlfong01 wrote:
Tue Sep 04, 2018 7:08 am
Now I am preparing a second set of Rpi + demux quad I2C level shifter for swap testing of the P82B715 bus extender.

P82B715 I2C Bus Extender Testing Notes

Quad I2C Level Shifter x 4 is now manually selected all.
by tlfong01
Tue Sep 04, 2018 7:08 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

... Now I have made a 60cm long I2C cable, 1. SDA and Gnd twisted [/color] 2. SCL and Gnd twisted [/color]Both with a pitch of about 2 turns per inch. P82B715 I2C Bus Extender Testing Notes Now I am preparing a second set of Rpi + demux quad I2C level shifter for swap testing of the P82B715 bus extender.
by tlfong01
Fri Aug 24, 2018 9:22 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

... of 4 wires of two twisted pairs: 1. SDA and Gnd twisted [/color] 2. SCL and Gnd twisted [/color]Both with a pitch of about 2 turns per inch. P82B715 I2C Bus Extender Testing Notes Appendix P82B715 Datasheet - NXP 2009 https://www.nxp.com/docs/en/data-sheet/P82B715.pdf
by tlfong01
Tue Aug 14, 2018 1:26 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: favorite replacement for 8-channel Bi-directional Logic Level Converter - TXB0108
Replies: 3
Views: 2298

Re: favorite replacement for 8-channel Bi-directional Logic Level Converter - TXB0108

... at 100kHz/400kHz, over 1 meter, you might need an extender, such as P82B715) 11. Many more requirements I forgot. ;) What I have tried or hope ... posts on level shifting (General) RE: RELAY MODULE KY-019 5V Post by tlfong01 » 2018-Jun-14 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&p=1328090&hilit=logicl+level+converter+shifter#p1328090 ...
by Brandon92
Mon Aug 13, 2018 4:29 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

Many thanks for your advice and recommendation. So I have ordered 20 pieces of P82B715 (DIP8) from TaoBao, at RMB 8 each. SF Express delivery usually takes less than 2 days. BTW, I mentioned I read people saying they are do I2C up to 100 meters, I think they all ...
by Brandon92
Fri Aug 10, 2018 7:53 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 132911

Re: Relay Module KY-019 5V

... it will invert you signal. This explain what I wrote at the start. And you can better use a product that is designed for this task. For example: P82B715 , but there are many more ;) I2C Bus Operation Over 50 Meters of Twisted-Pair Wire Please confirm if this is right or not

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