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by tlfong01
Fri Jan 25, 2019 11:54 am
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4269

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

... photo and thermal sensor. Too Many I2C Pullups Overloading TSX0104 I can ping PCF8591 alone without any problems. But if I put 3 devices (M017, DS3231, and PCF8691) on, then i2cdetect has intermittent no detect problems. I guess too many 4k7 resistors are overloading TSX0104. So I need to think ...
by tlfong01
Fri Jan 25, 2019 7:40 am
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4269

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

... and found everything OK. The ping program can now ping 3 devices: DS3231, MCP23017, and PCF8591. ... # pingI2cDev167 tlfong01 2019jan25hkt1528 # Rpi3B+ Raspbian stretch linux 4.14.34-v7+ arm python3.5.3 # Program ...
by tlfong01
Thu Jan 24, 2019 2:56 pm
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4269

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

... Cat Home DIY Q&A - Real Time Clock How To Python Program to Ping DS3231 and MCP23017 I opened the new topic on RTC and listed a ping RTC program ... and IOX MCP23017. The listing is given below. ... # rtcIox01 v1.65 tlfong01 2019jan24hkt2245 # Rpi3B+ Raspbian stretch linux 4.14.34-v7+ arm ...
by tlfong01
Thu Jan 24, 2019 1:10 pm
Forum: Automation, sensing and robotics
Topic: Cat Home DIY Q&A - RTC How To
Replies: 1
Views: 545

Cat Home DIY Q&A - RTC How To

... ESP8266-12. Now I am starting a new guy called RTC (Real Time Clock) DS3231. This device can do real time clock, temperature sensor, and also ... Clock Test Program) ... # DS3231 Real Time Clock Test Program v1.62 tlfong01 2019jan24hkt1726 # Hardware Software Description # Rpi hardware ...
by tlfong01
Thu Jan 24, 2019 12:58 pm
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4269

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

MCP23017 Testing - Writing and Reading A Register RTC DS3231 Ping/Hello/WriteReadRegister Program I read my old posts on MCP23017 ping program but found another similar program on RTC DS3231. This reminds me that at that time I found MCP23017 unstable, ...
by tlfong01
Thu Jan 24, 2019 8:30 am
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4269

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

... Post for Reference MCP23017 IOX Write Read Register V1.4 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&start=200#p1344684 DS3231 RTC Write Read Register V1.5 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&start=225#p1345103
by tlfong01
Thu Jan 24, 2019 6:56 am
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4269

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

... (MCP23017 Write Read Register MCVE Program V1.4, V1.5) https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&start=225#p1345103 (DS3231 Write Read Register Program) https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&start=225#p1345488 (RTC DS3231 Test Program) ...
by tlfong01
Fri Dec 21, 2018 8:50 am
Forum: Python
Topic: GPIO.input voltage levels vs edge detection
Replies: 430
Views: 96636

Re: GPIO.input voltage levels vs edge detection

... not have big problems in this part, unless later you want to connect more that one mcp23017, and also other i2c devices such as real time clock DS3231, then you might have data transmission problems.
by tlfong01
Fri Dec 07, 2018 7:59 am
Forum: Automation, sensing and robotics
Topic: Reading old weight scale
Replies: 124
Views: 30273

Re: Reading old weight scale

... of 10kHz: (HX711 Control Signal Timing) RE: READING OLD WEIGHT SCALE - tlfong01 2018dec01 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=227137&start=50#p1398970 ... DS3231&start=325 (Rpi generating 200uS pulse) RE: RELAY MODULE KY-019 ...
by tlfong01
Fri Dec 07, 2018 6:34 am
Forum: Automation, sensing and robotics
Topic: Reading old weight scale
Replies: 124
Views: 30273

Re: Reading old weight scale

Any bad I2C device could corrupt all the I2C channels . MCP23017 Evaluation Board Newbie Version 0.1 I also found RTC DS3231 much more stable than MCP23017. Effect of very long I2C connecting wires I also compared the effect of using long, 90 cm wires, with short 30 cm wires. I surprisingly ...
by tlfong01
Thu Dec 06, 2018 9:13 am
Forum: Automation, sensing and robotics
Topic: Reading old weight scale
Replies: 124
Views: 30273

Re: Reading old weight scale

... a 10uF tantalum cap very near to the on the 5V power connector, and 10uF and 0.1uF tantalum very near to the MCP23017 power pins. I also found RTC DS3231 much more stable than MCP23017. So in case of unknown MCP23017 errors, I usually check if RTC DS3231 is OK. In other words, DS3231 is a canary ...
by tlfong01
Wed Dec 05, 2018 12:21 pm
Forum: Automation, sensing and robotics
Topic: Reading old weight scale
Replies: 124
Views: 30273

Re: Reading old weight scale

Newbie notes on setting up Rpi Raspbian Version 2018Nov Desktop MCP23017 Programming - Memory Refreshing Old Posts DS3231 32kHz HC14 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&p=1332230&hilit=DS3231#p1332019 DS3231 TSX0104E HC14 CD4040 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158&hilit=DS3231&start=100#p1332019 ...
by tlfong01
Wed Sep 26, 2018 2:02 pm
Forum: Python
Topic: GPIO.input voltage levels vs edge detection
Replies: 430
Views: 96636

Re: GPIO.input voltage levels vs edge detection

... way of using tables is weird, but very powerful, and that's the way I like it . I will start my first warm up exercise by writing a driver for I2C DS3231 Realtime Clock. I will be over killing or abusing the data structure table object as a way to learn, and that's the way I like it, aha, aha , ...
by tlfong01
Thu Sep 06, 2018 2:28 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... P82B715 I2C Bus Extender Testing Notes Now I have connected three more I2C devices to I2C Bus Channel 3: MCP23017 Iox # 7 PCF8591 ADC/DAC DS3231 RTC + EEPROM Now the greedy hobbist has 7 MCP23017s or 16 x 7 = 112 GPIO pins! Greed is Good - Gordon Gekko https://en.wikipedia.org/wiki/Gordon_Gekko
by tlfong01
Tue Sep 04, 2018 8:55 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... 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 time and stalled my DHT22 Humidity and Temperature Sensor project. I found MCP23017 ...
by Brandon92
Fri Aug 24, 2018 1:40 pm
Forum: Python
Topic: GPIO.input voltage levels vs edge detection
Replies: 430
Views: 96636

Re: GPIO.input voltage levels vs edge detection

... GPIO is hard Well, there is another important reason I told your earlier when explaining why I don't go the easy linux kernal driver way for DS3231 and DHT22, but use MCP23017 instead, because I learn more new things the hard way. I meant that you Rpi could not be damaged, if you connect ...
by tlfong01
Fri Aug 24, 2018 8:49 am
Forum: Python
Topic: GPIO.input voltage levels vs edge detection
Replies: 430
Views: 96636

Re: GPIO.input voltage levels vs edge detection

... GPIO is hard Well, there is another important reason I told your earlier when explaining why I don't go the easy linux kernal driver way for DS3231 and DHT22, but use MCP23017 instead, because I learn more new things the hard way.
by tlfong01
Sun Aug 19, 2018 8:41 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... Ah, I am only scratching the surfaces of the following things. 1. RTC DS3231 with temperature sensor 2. IOX MCP23017 3. THS DHT22 Humdidity and ... MCP23017 and not simple Rpi GPIO RE: RELAY MODULE KY-019 5V - Post by tlfong01 2018-Jun-08 https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=77158&start=25#p1325530 ...
by tlfong01
Thu Aug 16, 2018 5:10 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... modules: i2cutil01.py, rtc01.py, iox01.py , and now starting the new module, hts01.py . 2. i2cutil01.py I started rtc01 testing the following RTC DS3231 functions: '0' 'Write and read back Day Register '1' 'Repeat write 0x5a to Rtc Day Register (for scope) '2' 'Read and print temperature once ...
by tlfong01
Wed Aug 15, 2018 7:47 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... cables, I am moving on to test the MCP23017 controlling DHT22. But the other sensor HDC1080 also arrived, so now I have 12 sensors to test: 1. RTC DS3231 temperature sensor x 4, 2. DHT22 humidity and temperature sensor x 4, and 3. HDC1080 humidity and temperature sensor x 4. I wired up one HDC1080 ...
by tlfong01
Wed Aug 15, 2018 3:23 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... FOR 8-CHANNEL BI-DIRECTIONAL LOGIC LEVEL CONVERTER - TXB0108 tlfong01 2018aug14 https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=217340#p1352588 ... 2. Use 15cm long gkt to connect one TXS0104E 5V0 SCL SDA output to RTC DS3231.(B) 3. Use 15cm long gkt to connect another TXS0104E 5V0 ...
by tlfong01
Mon Aug 13, 2018 4:24 am
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... doing python coding myself, and why not save time by using third party packages or libraries, such as pipgio. I did google around for mcp23017, ds3231, and dht22 libraries and example programs. But I found studying other programmer's programs and modifying them to adapt my requirements is often ...
by tlfong01
Tue Aug 07, 2018 1:45 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

DHT22's temperature is typical +- 0.5 degree C (max +- 1 degree C) and humidity +- 2% accurate, better, but not that much better than DS3231's 3 degrees accuracy. Sampling time = 2 seconds. Now the timing diagram. I need to tell MCP23017 to send the following pulse - Send Idle = High Start ...
by tlfong01
Tue Aug 07, 2018 1:18 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

tlfong01 wrote:
Tue Aug 07, 2018 1:05 pm
DHT22's temperature is typical +- 0.5 degree C (max +- 1 degree C) and humidity +- 2% accurate, better, but not that much better than DS3231's 3 degrees accuracy.

Sampling time = 2 seconds.
by tlfong01
Tue Aug 07, 2018 1:05 pm
Forum: Automation, sensing and robotics
Topic: Relay Module KY-019 5V
Replies: 488
Views: 133273

Re: Relay Module KY-019 5V

... DHT22's temperature is typical +- 0.5 degree C (max +- 1 degree C) and humidity +- 2% accurate, better, but not that much better than DS3231's 3 degrees accuracy.

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