Fetching latest commit…
Cannot retrieve the latest commit at this time.
|Failed to load latest commit information.|
This design is a clone of Leaf Labs Maple Mini board (called MM4) with the following variations from the original: - 0.8 inch pitch between connectors rather than 0.6". This means dual rows of sip connectors are required rather than a 40 pin dip (a socket layout can easily be defined for either LeafLabs or MM4 using 3 sip connectors.) - identical pin functions except for the above mentioned pitch change. - two layer layout in Eagle which can be modified with the free version of Eagle (original was done with Eagle v6.1). Ground planes that are as large as practical are used given the two layer constraint (modification to internal power/ground planes is, of course, fairly straightforward, but requires the much more expensive Eagle license). - 64 pin processor that can be STM32F10xC/D/E orSTM32F4 or STM32L1 series. This means the F1 chip variants with larger memories can be used or the L1 low power series (F1 and L1 require two solder bridge jumpers to be installed), or the faster Cortex-M4 F4 series. - considerably less detailed top silkscreen layer in this version of MM4. - The USB termination function has been re-implemented with a dedicated USB terminator chip that contains the termination resistors and the signalling resistor to describe the board to an up-stream host as a full speed USB peripheral. The disconnect function is then separately implemented with an open collector inverter. The original implemented the signalling and disconnect via a transistor/resistor network.