Adapting graphical LCD with touch screen to ChipKIT UNO32

ChipKIT is an excellent substitution board to Arduino. It offers better performance as it is based on PIC32MX320F128 microcontroller based on 32-bit architecture. The microcontroller has 128K of Flash and 16K of SRAM on board. Having Arduino Uno shape factor ChipKIT offers more 42 programmable pins. ChipKIT like Arduino can be programmed with a bootloader that communicates to PC through USB-to-USART converter chip FT232RQ. Digilent has developed an STK500v2 based bootloader that works on PIC, so it is easy to program using AVRDUDE tool. Besides that, they adapted an Arduino environment to work with ChipKIT boards. It’s called Mpide. It also supports Arduino boards, but it aims to program ChipKIT boards. Programming experience is pretty same as for Arduino, and even most of the examples written for Arduino work on ChipKIT. This is true since there is no specific hardware elements touched like program memory or EEPROM. As you know Arduino is rich in hardware support libraries as all shields are designed for Arduino. Latecomers like ChipKIT even if they are hardware compatible may have some difficulties with library integration due to the different architecture.

Continue reading

Rethinking AVR DDS3 signal generator project

These things happen all the time. When you start a new project but from the beginning start feeling that it’s not what you wanted. Usually, they end up collecting dust. I think there is nothing shameful because it is better to fail than do nothing. There are thousands of examples where people, companies start new projects with enthusiasm but they never reach the daylight. But without those efforts, we wouldn’t see other great projects and products. Not all of them are made from the first try. It’s been over a year since the announcement of AVR DDS3 signal generator. As you have noticed, there is no progress so far on it. And I am going to give up on it for a couple of reasons. From the beginning, I didn’t feel comfortable with it.

Continue reading

AVR DDS3 boards have arrived

Finally some update on AVR DDS3 signal generator. Circuit is practically done and PCBs are made. I decided to go with two microcontrollers on board to make it more functional. One microcontroller Atmega328P is gonna be dedicated to user interface and signal generator control. Second Atmega88 is gonna be used for signal generator only. This will give un-interruptable signal output while changing parameters or simply doing signal sweeps. Simple keypad should be convenient for entering frequency values and menu navigation.

Continue reading

Project demo on STM32F103RBT6 using GCC

STM32F103R board is a simple and easy development board to learn STM32 microcontroller programming. Its heart is STM32F103RBT6 ARM Cortex-M3 microcontroller with 128K of Flash and 20K of SRAM memory. It can be clocked at the maximum 72MHz frequency and is considered to be a medium-density performance line microcontroller. Other features include USB, CAN, seven timers, 2ADCs, and nine communication interfaces. Development board has several nice features to get started. First of all, it has an RS232 interface for communicating and accessing bootloader. There also is a USB 2.0 full speed interface connector that also can work as the power supply. Next is a JTAG connector to program microcontroller using tools like J-Link adapter. Two push buttons and two programmable LEDs are hardwired to MCU pins alongside all I/Os connectors.

Continue reading

Harvesting energy with home made solar thermal collector

Nearest star from Earth is Sun. And it emits a massive amount of energy which is free. No surprise many people try to get most of it with minimal cost. Photovoltaic solar panels still have low efficiency and yet are quite expensive. Every day we hear how their effectiveness is increased by introducing new technologies. Anyway, solar panels require direct Sun which in some regions doesn’t appear very often. So how we can get this energy with almost no initial cost? The easiest way to do so is to build a solar thermal collector. You can find lots of high efficient commercial collectors. They look great and at some level works in the winter time when Sun shines. I decided to go simpler. I need hot water only in spring, summer, and fall. In the winter time, I burn wood to heat the house and so water. In the summertime, I usually boiled water using an electric boiler which generates nice bills at the end of the month. No more… So I started this project which is still in testing phase. But seems to work fine. Lets go through build process how I made a simple solar collector using old…

Continue reading

Driving Graphical LCD with STM32F103ZET6

STM32F103ZET6 board comes with 3.2 inches graphical LCD which features an ILI9320 controller. Equipped LCD is capable of displaying 252144 colors when driven in 18-bit mode. We are going to run it in 16-bit mode, so we are limiting it to 65K colors. LCD driver is based on existing code found on the internet which was originally developed for STM3210E board. Only minor modifications were needed like assigning right control pins.

Continue reading

Connecting STM32 USART to standard I/O streams in GCC

In many situations when working with STM32 microcontrollers, you will want to output text strings. There is no need to write specialized functions that output specially formatted strings as it is hard to keep up with various cases. It is convenient to use standard I/O streams and its library functions that allows sending formatted data streams. Arm GCC toolchain comes with newlib C library from Redhat, and so it isn’t specially designed for embedded toolchain. To use stdio functions we have to take care of several syscals so-called “stub functions.” These functions usually are provided by operating systems like you would write C programs in Windows or Linux. In our case, we aren’t using any OS, os to avoid error messages while compiling we have to provide these function declarations where most of them are dummy implementations. It’s not something new pick one that you find on the internet. I noticed that it was written for STM32 Discovery.

Continue reading