Minimalistic STM32F042 scope

In many cases oscilloscope is used to test low voltage and low frequency signals. This is what any low end oscilloscope is capable of. I think that proper oscilloscope should be on every hobbyists bench. But still there might be various reasons not to have. As quick fix to this problem might be a DIY solution. Tomeko have build really minimalistic scope project on STM32F042 ARM Cortex microcontroller. It accepts single channel, single voltage range signals and streams it to PC via USB FS with libusb as driver. Scope’s sampling frequency is 480kSps at 8-bit resolution. Signal is captured in real time Windows application which can record signal to file up to 512M samples. This is enough for simple measurements and monitoring. The great thing about this is that circuit is really minimalistic with only few passive components on it. Because of this simplicity, it will never replace any oscilloscope, but it could find its use simple signal debugging is required. In other hand it can serve as additional module in some project where you might want to have a… Continue reading

Handy ARM Pro mini development board for fast prototyping

ARM microcontrollers are slowly taking over 8-bit micros like AVR or PIC. In many cases they are much cheaper and offer greater performance. Open source and free tools are getting more robust so programming ARM Cortex became even simpler. This is probably why we see lots small ARM based development boards of any flavor. Zapta has also built pretty small (38.1mm X 19.7mm) ARM Pro Mini board based on NXP ARM Cortex-M0 microcontroller. Its small form factor allows integrating it in to various size projects while keeping maximum functionality and connectivity. It can also be used in solder-less breadboard prototyping. To make things simpler, he prepared board level library to work with interfaces. Few program demos will help to get started pretty fast. Continue reading

ARM Cortex-M0 development board with battery power in mind

There are tons of ARM development boards that are of various sizes shapes and power. But when things turn towards battery-operated gear, the list shrinks down. We expect battery operated and portable electronics part to be small size and include all battery management circuit along with charging and DC/DC conversion. Vsergeev introduces his version of a small ARM Cortex-M0 powered board. He wanted his board to be small, battery operated (USB), and below the price. The board size came out to be 70x43mm. It carries an NXP LPC1114FDH28 32-bit ARM Cortex-M0 microcontroller. Additionally, there is a 16-Mbit SPI FLASH memory. As mentioned before, the board can be powered by a USB (Mini-B) or LiPo battery. The battery can be charged with an onboard LiPo charger IC (MCP73831T). There are 4 LEDs on board, along with two pushbuttons and 2 DIP switches. For more IO capability, there is also an I2C 8 additional I/O pins expander. So there is a total of 16 I/Os on the header, SWD for flashing and debug, and 6 pin UART header that matches popular FTDI… Continue reading

There is always a choice between cost and performance

Some time ago it was quite obvious which microcontroller you had to pick for your next project. For low cost and slower applications you simply selected 8-bit micro. When design needed to do intense processing you most likely had to go with ARM or other solution. Today situation is a bit different. Sometimes you are in situation when lowest end ARM microcontroller is way cheaper than 8-bit micro and it still offers several times better performance. And final decisions sometimes are driven by loyalty, experience or ecosystem. Lets not get in to that kind of discussion. Every microcontroller family has to offer something unique that looks attractive in particular situations. ARM Cortex microcontrollers have great position right now because they have something to offer all embedded hardware niches. Lets take a quick look at two development boards from STM where one carry ARM Cortex-M0 and another ARM Cortex-M4F microcontroller. You can get both discovery boards from Newark really cheap. The first one is called STM32F0Discovery, The name already says that it is based on ARM Cortex-M0 microcontroller STM32F051R8T6. It has… Continue reading

Software USB implementation on ARM Cortex M0+

Smaller ARM microcontrollers don’t have native USB interface. So you are left with couple choices – use dedicated level converter like FT232 or try to bit-bang software based protocol. Obviously, first choice was the easiest one, until now. Guys from have successfully implemented software based low speed USB peripheral which is lightweight (~4KB flash footprint) and includes HID stack. In order to run code out of box, they assembled Zero Gecko 110 breakout board with EFM32ZG110 mcu which is small size and has most periphery for building devices, debugging and programming. This achievement will allow building cheaper and smaller footprint devices using ARM cortex M0+ and probably other micros that don’t require fast speed USB. Continue reading

Miniature ARM baord

ARM development boards always been bigger, and more complex than other 8-bit systems. But things are different now – ARM also can be smaller but yet more powerful embedded devices than PICs or AVRs. We already know that ARM processor can be as small as 8 pin chip. LPC810 ARM Cortex M0+ is one of great examples. And you know you don’t need much to get it running. Jan built probably smallest ARM device with this chip which can be used in many cool projects where bigger processing power is needed. For instance in wearable electronics projects. The board (which is called Catweazle) consists of LPC810 processor in DIP package, 3.3V LDO linear regulator and LED which indicates when it is set to ISP programming mode. Controller can be programmed via UART by using any USB TTL cable and standard software like Flash Magic. Board has 6 I/O for normal use. Chip carries 4K of flash, 1 K of SRAM, 2 timers, hardware SPI, I2C and UART. And most importantly this is a true 32-bit controller for $1 Continue reading