Redesigning mobile phone with rotary dial

Rotary dials are long gone since everything went digital. Now every device is equipped with keys or touch sensitive input interfaces. But if you feel a little nostalgic about old times you may find this project really interesting. This is a custom made mobile phone with rotary dial for input. We already know that building mobile phone isn’t that hard when you already have GSM modules around. All you need it so hook everything to microcontroller and LCD and you are up to go.

jaromir instead of adding buttons or touch sensitive LCD went with simpler but yet interesting solution – a rotary dial. The phone is controlled with 8-pin DIP NXP LPC810 ARM Cortex-M0+ microcontroller. He had to squeeze everything to fit 6 IO pins. Shift register solves a lot here. No matter if it looks cool, making calls, entering PIN numbers can be real pain, but it works. As a phone it has huge enclosure due to large rotary dial size. You will definitely amaze your mates when taking calls. More pictures of it at Picasa.

How much should ARM development board cost?

It is no surprise that ARM microcontrollers become number one choice in many areas. One thing is that in many ways 32-bit ARM can be cheaper that other micros like AVR or PIC. Smaller price and better performance makes decision even easier. Developing tools also evolved in to user friendly solutions. You can see many ARM Cortex development boards made by different manufacturers for about $10. But are there really cheap ones that would have all necessary means to start developing projects? By means a have in mind, basic circuitry to keep chip running, programming and debugging interface and so on.


It appears that Development board can go as low as $4. Cypress Semiconductor offers Cy8CKIT-049-41XX development board that has 32-bit ARM Cortex-M3 microcontroller running at 48MHz. Board comes with USB to serial bridge part which can be easily snapped of when deployed. Board also comes with CapSense interface, user LED, push button and all GPIO pin connectors.

Nucleo-F401RE Arduino shape with Cortex-M4 power

STMicroelectronics Nucleo boards are another way of prototyping with ARM Cortex-M microcontrollers. The idea was to get closer to Arduino interface, but still have ARM power and versatility. The shape of Nucleo board is somewhat close to Arduino Uno, just a bit wider so it could carry two types of connectors. Lets look at Nucleo-F401RE – one of four boards available now.


First of all it features ARM Cortex-M4 STM32F401RET6 microcontroller which of course have FPU module and DSP instructions. There are 512KB of flash and 96KB of SRAM on chip and can be clocked up to 84MHz. Any Nucleo board have Arduino UNO compatible headers where most of Arduino shields can be plugged and used for fast prototyping. Other pins are brought out by using Morpho headers: Continue reading

ST-LinkV2 Programmer for the STM32

STM32 is the basic kit which everyone looks forward to when they need an exposure to 32-bit set of controllers. The good thing is that it’s cheap powerful and you get support from all over the world. Although a lot of debugger exist in the market from low cost t to some that are very costly. This programmer is a low cost programmer as well as debugger and have the basic necessity function. The debugger is small as well as easy to carry and not clumsy like the existing programmers.


The board takes power from the USB and hence no external adaptor is needed. Once you have installed the necessary drivers, you are ready to go.  For those interested in the project, a schematic has been provided and the source code can eb requested from the owner. However if you are too lazy to build one yourself, you can get it directly from the owner since he has some spare copies of the programmer.