Tech Info, Learn Things and Other Fun Stuff

Raspberry Pi and Graphic Display Interfaces

Posted by Vytas Sinkevicius on

Raspberry Pi and Graphic Display Interfaces

Here is a project that uses our 128x64 Graphic Display / User Interface for the RPI 3. The user interface module has a 1.4" LCD, three pushbuttons (UP, DOWN, ENTER) and a bi-color (Red/Green/Amber) LED for status indication. To operate off the RPi 3, the display interface is resource heavy: it uses a total of 19 GPIO lines! 8 for LCD data bus 5 for LCD control lines 1 for LCD backlight 2 for Status LED 3 for Push Buttons The test software is written in "C" using the Geany compiler. The software features: 7 lines of display Font table...

Read more →

Raspberry Pi and Wireless RS485 Data Acquisition

Posted by Vytas Sinkevicius on

Raspberry Pi and Wireless RS485 Data Acquisition

We have just completed testing our re-designed wireless hat for the Raspberry Pi 3 and our Zigbee to RS485 converter for the 900 MHz S3B series from Digi. This system worked right out of the box with simple programming using the Digi XCTU program. The RPi 3 was configured for Modbus RTU protocol and using the new RPI3 wireless hat by VP Process Inc. The analog 8 channel 4-20 mA input module is connected to the RS485 to wireless converter, which is also available in a DIN rail enclosure. The typical application for this would be where the data acquisition...

Read more →

Raspberry Pi and Wireless Temperature Sensors

Posted by Vytas Sinkevicius on

Raspberry Pi and Wireless Temperature Sensors

Wireless temperature sensors have a wide range of applications. The VP-TX195 by VP Process Inc. is a new 5 point wireless temperature sensor that operates on 2 AA cells and communicates with the RPi with Zigbee. The Raspberry Pi wireless shield will operate with either the 2.4 GHz Zigbee modules or the 900 MHz Series S3B modules. The wireless 5 point temperature sensor uses 10K thermistors, and uses the same circuitry covered in a previous blog post found here. The first temperature sensor is located on the PCB itself, and the other 4 temperature sensors can be located up to...

Read more →

Power Monitoring with PIC Processors

Posted by Vytas Sinkevicius on

Power Monitoring with PIC Processors

Power monitoring circuits are used in commercial applications such as data centers for two main purposes: monitoring power consumption and sending alerts when the current flow approaches the breaker limit. Typically data centers have large breaker panels (up to 42, 60, 72 breakers per panel) and use "CT strips" where the current transformers are on a strip in front of the breakers. Each phase power wire goes through the current transformer before it is attached to the breaker. These types of installations are done during the build stage and before main power is applied. The circuit shown above is used...

Read more →

Raspberry Pi, Zigbee and RS485 Wire Replacement

Posted by Vytas Sinkevicius on

Raspberry Pi, Zigbee and RS485 Wire Replacement

In applications that use RS485 and Raspberry Pi's, sometimes it is not always convenient to run wires from the controller out to the application hardware. Using two Zigbee modules as a "Wire Replacement" can be the answer you are looking for.   The devices used in this example are: Raspberry Pi as the controller Raspberry Pi wireless shield Wireless Zigbee to RS485 converter RS485 field module, in this example an 8 point relay module Zigbee Module (Pro Series S2B) as Co-ordinator (AT) Zigbee Module (Pro Series S2B) as Router (AT) For the test software, the RPi is sending relay info...

Read more →