This research paper presents the design and implementation of an open source multichannel EMG armband for hand gesture recognition. Initially a brief introduction about electromyography and similar researches is presented. Then, the general structure of the system is explained, after this it can be found the detailed description of the circuits used to acquire the signal, how the acquisition system was configured and how the communication between the EMG device and the computer was handled. Lastly, it is concluded that the device has an immense potential for EMG signal analysis and is cheap, easy to use and manufacture, however, it can be improved through the use of high precision chips like the ADC ADS1298, what gives the device greater acquisition capacities.