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Pi based SNMP Monitor
06/11/2017 at 09:12 • 0 commentsSo, I was called in at a local university for a discussion regarding an SNMP based environmental monitor - which would use a Raspberry Pi and have some temperature and humidity and other sensors attached to it and at the back of my head, I was screaming PI PURZA.
Anyways, they also need some relay connections and also possibly water spill detection, door open/close detection and such - I think all this can be still doen with the Pi Purza - I did start with a basic Sketchup drawing and a positioning check on a vero board.
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Populating the Pi Purza Boards
06/11/2017 at 08:50 • 0 commentsWell, this project was mostly done some months back, but the final task was to get all the Pi Purza PCBs populated, assembled, tested and ready for use in classes and to sell.
I asked [Noor Ahmed] to get started with the soldering of the PCBs, most difficult was the RGB LED and the RTC Crystal as I had forgotten to increase pad sizes for these and as we are not very with soldering of SMD parts, this was a big headache, in the end almost all boards work and just a few issues to resolve, before the final soldering of the 40 pin Pi header.
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Software Work
06/11/2017 at 08:35 • 0 commentsThis is the part, where I end up writing, copying, hacking code to get things to work.
My usual route in a project like this with many different components is to first try each and every thing separately with separate code, libraries and such - as usually there are examples available online for almost everything these days - especially many many THANKS to Adafruit.
So, I made a GitHub repo to record my work for the code part - this was being done on the VeroBoard prototype while the PCBs were on their way - these LOGS are not in order - https://github.com/zaidpirwani/PiMon
The prototype setup is shown
In the end, I had it in such a way that one of the Push Buttons would make the Pi Shutdown in a clean manner, the LCD would show current date and time and the IP of the network. The LCD also showed Temperature and Humidity values coming in from the DHT11 Sensor and the DS18b20 Sensor.I also had the LED blink once every second to show that the system was indeed working.
Still to do is the IR Sensor.
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The PCBs are Here
06/11/2017 at 08:27 • 1 commentWith all the components and circuit schematic finalized, I gave [MaazMobin] a crudely drawn schematic with components and my preferred pin numbers and asked him to design a PCB in EagleCAD.
He did so, then we sat together to finalize the component positions and then routing was done and finally SEEED Studio Fusion PCB Service was used to get the PCBs fabricated.
Maaz was good enough to put it on Github - https://github.com/maazmobin/pi_hat_eagle - this was his and mine first experience trying to make a PiHat with official dimensions and sizing.
I forked the repo and did some final modifications, mainly cosmetic wise, silk screen and other things.
https://github.com/zaidpirwani/pi_hat_eagle
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Finalizing Circuit
06/11/2017 at 08:12 • 0 commentsAs I started listing things down to connect with my Pi, I also realized I sometimes needed IR Sensor, sometimes a Buzzer and sometimes even a simple USART or SPI header was needed.
So, ended up with this list in the end:
Hardware (mentioned pins are BCM Pins)
OUTPUTS
- Nokia 5110/3310 LCD (RST,CE,D/C,DIN,CLK==24,8,23,10,11)
- LED (21)
- Buzzer (16 - with 2N2222)
- USB Powered Speaker
INPUTS
- TSOP17xx IR Receiver (20)
- 5x Push-to-Make Buttons (26,19,13,6,5)
- DHT11 Temperature and Humidity Sensor (17)
- DS18B20 Temperature Sensor (4)
- DS1307 RTC (SDA,SCL==2,3)
- USB WebCam
Libraries/Software Tools (used/planned to be used)
- Adafruit Nokia LCD Library
- Adafruit Python DHT Library
- Python RPI GPIO
- Wiring Pi
- LIRC
Device Tree (/boot/config.txt)
- IR Input (gpio-ir)
- DHT11
- DS1307 RTC
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The Old Times
06/11/2017 at 08:03 • 0 commentsIn the olden times, I used to make circuits around Raspberry Pi for everything, Sensors, LCD, Buttons and such.
This ended up with me doing much work which was repeated every time there was a Pi related project, so I started to list down the most common things I used with a Pi.
- Buttons
- LEDs
- LCD
- Temperature Senor
- RTC