Hi all! Here’s one of the last board I design the last year. On 2016, I develop the Dual USB Serial and I2C Converter board. Although this board works fine, it has a couple of lacks. First one, is that to use the both converters, you need two free USB ports. Is a minor problem today with USB hubs, but you need the hub and also two USB wires. And the other problem is that this board uses mini-USB connectors. Of course today you can still find it, but aren’t as common as the micro-USB wires. For this two reasons, I decide to upgrade the board, add the micro – USB connector and put a USB hub inside it. Because I choose a 4-port USB hub, I use also 4 USB serial converters. With some addons, you can select power supply value (5V, 3V3), serial levels (TTL, RS232) and GPIO functions in an independent way for each converter. So, let’s see how works this USB Serial Star, a 4 in 1 USB to Serial and I2C Converter.
Hi all! I’m really busy this year so I can’t post all the projects where I’m involved. Here’s one of the design I do last year for a client. He wants to measure the voltage of a car battery and set a couple of alarms when voltage falls below a defined values. Also, he wants to put the device in the relay box of the car, so the design needs to have a relay form factor to easy integration. So, after a couple of iterations, here’s the final design of the battery monitor.
Hi all! After a really busy months, I come back with a small tip. I start again work with PICs some years ago, and since then, I usually use the Pickit 3 programmer from Microchip. It’s a really great tool, with official support, online updates, and I never have a problem with it. But a couple of years ago, I discover the Mikroe products, both compiler for PIC and the programmer they have to program more tan 1000 PIC microcontrollers, the Mikroprog programmer
Mikroprog is bigger in size than Pickit3, and comes with a flat 10-pin wire assemble inside the box, so you can’t remove this wire. Pickit 3 has 6-pin female connector just to plug it on the board header for programming.
Both devices has the same USB connector for PC management: USB mini:
The problem with this two programmers is the programming connector. As you can see in the following image, both programmers has different connectors and pinout for programming:
The pinout of the programmers are shown on the next image: on the left side, Pickit 3 pinout and on the right side, Mikroprog pinout:
So, to use old boards thas has Pickit 3 header with Mikroprog programmer, you definitively need an adapter to have the signals on the same order. Is really simple to implement, just need to cross the signals. Here’s the schematic of the adapter:
With the connectors and a small piece of prototype board, it just take 10 mins to make it one:
So, with this simple adapter you can use both programmers on boards that have a Pickit3 programming header.
I’m very busy last months working on new boards and projects, sorry for the delay!
Some months ago I review the DSETA board due the obsolescence of the microcontroller. I use this board in some projects succesfully. But when I try to manufacture a batch of this boards, I found that the microcontroller (AT89C51RE2) was obsolete. So, the board needs an update to change the microcontroller and maintain most of the features that it has. Now that Microchip buys Atmel, obsolescence and samples will not be a problem.
To replace the RE2 microcontroller, I choose one very similar, the AT89C51ED2 microcontroller. Mainly because it shares most of features with the old one and footprint and pinout is almost the same, so replacement is relatively easy to do.
Come in and you can see the new board features, changes and more!!
Hi! First of all, Happy New Year 2017! I hope all of yours starts the new year with good intentions. The mine one is write frequently here. Family and work don’t let me much free time but I’ll try it!
For several months I’m working with FONA808 modules from Adafruit to make a portable, web-based locating system. This modules are based on the SIM808 module from SIMCOM manufacturer, and integrates both GSM and GPS transceivers in one 24x24mm package. The Adafruit board includes this module and also some electronics for choosing voltage levels, battery connection and charger. Because I need to test and programming some of this modules, I decide to make an specific PCB for it, allowing the programming and debugging via PC, wich is more comfortable that use a microcontroller for all these tasks. I use the MCP2221 USB-Serial bridge and add some electronics to give the board more functionality. So it has a connection for a 3.7Li-Ion battery, battery charger, manual pushbutton to turn on/off the module and also several led’s to indicate the status of the different elements and network connections. So, let’s go for it!
UPDATE: Here’ the BOM file, I forget upload it: BOM_PIC_DATALOG_V1.0_WEB
UPDATE: Also in Adafruit’s blog. Thanks!
Hi all! I’m continuing here with the last board I design and now I’m continuing testing. It’s a battery-powered small datalogger based on a PIC18F2620 microcontroller. The idea comes a few months ago, talking with a friend. He needs something to monitoring temperature and humidity inside a sea container, for a three weeks travel from Spain to China. Low consumption is important, in order to have maximum autonomy with a small battery. I use a HDC1050 temperature and humidity sensor, and a TEMT6000X01 ambient light sensor. The collected data is stored on a micro SD card. Also the board has a RTC for timestamp, a Li-Ion battery charger, user pushbuttons and leds, and a MCP2221 USB bridge to communicate with the board and configure some parameters through software. Let’s see the board in detail!
UPDATE: Some places where the project appears. Thanks to all!!
Hi all! After a couple of months with a lot of work, I come here again with the last board I develop before Christmas. It’s a dual USB serial and I2C converter based on two MCP2221 Microchip 2.0 USB-Serial bridges. I develop it as a need on my work with the last project I’m involved. I need to monitor a serial communication between two devices. With only one converter, I must choose between RX and TX lines to monitoring the traffic. With this solution, I can listen at the same time TX and RX lines, so the monitoring is more easy. And with a software like Docklight (you can download a free evaluation copy here), you can choose the monitoring option to display both channels. After the break you can find all the technical info of the board!
Hi all! Here’s the new project where I’m working a couple of days. Since I develop the SIM900 module and test it, I don’t work with it. Also, I’ve got at home some samples of the MCP2200 USB bridge that I want to test it. So make an USB interface for this board was the perfect idea! This allows to use the SIM900 board with a PC, Raspberry or similar, with the plus of no need external power supply or control signals. Just plug the USB cable on the board and start communicating with the world!
UPDATE: Thanks to Rando, now you can order this PCB on OSH Park. Thanks!!
UPDATE: If you’re interested in mount the board yourself, now you can download the Bill Of Materials (BOM). Happy welding!
Hi all! With a bit of delay, here’s my last work, a PICnano breadboard based on the PIC18F2550 microcontroller. I have in mind a new project and I want to use an small board, like the Arduino Nano board. This new project is battery powered (3,7V Li-Ion battery). After checking the schematics of the Arduino Nano, I see that the microcontroler is powered at 5V. Of course, I can unmount the linear regulator (U3) that is on the board, and bypass the VIN to the microcontroller power supply. But I think it’s funny try to develop a new module when you’ve access to the microcontroller power supply! Also, I want to work with PIC microcontrollers after many years, so here’s what I design!
UPDATE: This board appears on Adafruit’s blog. I’m very happy with this, it’s a great recognition and I only can say Thanks!!!
I’m continuing working with Juan Brito and Danny Macancela from the blog Desafio Ecuador, developing new boards to bring near the technology and programming languages. Our last work is a board to use with the Raspberry Pi and focused to learn Python. The board has the basic elements to start with this language. Also, with the develop of the PCB we remove the wiring, avoiding troubles with connections, inversion polarity…So with this board you only focused in the software develop, because the hardware side will work!