Underdog
About the Underdog PCB
Underdog is an open source AVR/Arduino PCB design by turboedge, published on GitHub under the GPL-2.0 license. It is a 2-layer board measuring 100 × 99.8 mm, with 202 components from 46 distinct parts.
Its main chip is the ARDUINO_MEGA_SHIELD, from the AVR/Arduino family. Other key parts include the IXDN602SIA, MPXH6115A6T1, TS2940CP50, MPXH6400AC6U and MP6600GR-Z. By type, the board carries 76 resistors, 35 capacitors, 33 diodes, 22 LEDs, 12 transistors and 10 connectors.
It belongs with the usb & debug tools designs in this gallery.
From the project
EMS boards powered by Speeduino
The reset button was added as the only reset connection made to the microcontroller to prevent unwanted resets from USB connected devices. There is a caveat to this arrangement though. While the first time a firmware is loaded it will go on without intervention, subsequent times will require the user to hold the reset button down then release the button when the program starts the upload process. If the upload does not start right away go back and try again.
Main components on the Underdog
Underdog bill of materials (BOM)
202 components, 46 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | IXDN602SIA | SOIC-8_3.9x4.9mm_P1.27mm | IC2, IC3 |
| 1 | MPXH6115A6T1 BARO | NXP_Pressure_Sensor_SSOP | U1 |
| 1 | TS2940CP50 | TO-252-2 | U2 |
| 1 | MPXH6400AC6U MAP | NXP_Pressure_Sensor_SSOP | U3 |
| 1 | MP6600GR-Z MP6600 | QFN-24-1EP_4x4mm_P0.5mm_EP2.7x2.7mm_ThermalVias | U4 |
| 1 | ZV14K1206201NIR1HT B72520E0140K062 | C_1206_3216Metric | U5 |
| 8 | NCV8406BDTRKG NCV8408BDTRKG | TO-252-2 | Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8 |
| 4 | NCV8402ADDR2G NCV8402AD | SOIC-8_3.9x4.9mm_P1.27mm | Q9, Q10, Q11, Q12 |
| 1 | External MAP Conn | SolderWirePad_single_1mmDrill | J1 |
| 1 | INPUTS | Molex_Micro-Fit_3.0_43045-2200_2x11_P3.00mm_Horizontal | P1 |
| 1 | OUTPUTS | Molex_Micro-Fit_3.0_43045-2400_2x12_P3.00mm_Horizontal | P2 |
| 1 | SER0 | Pin_Header_Straight_1x04_Pitch2.54mm | P3 |
| 1 | SER3 | Pin_Header_Straight_1x04_Pitch2.54mm | P4 |
| 1 | SER2 | Pin_Header_Straight_1x04_Pitch2.54mm | P5 |
| 1 | SPI0 | Pin_Header_Straight_1x04_Pitch2.54mm | P6 |
| 1 | SPI1 | Pin_Header_Straight_1x04_Pitch2.54mm | P7 |
| 1 | CAN | PinHeader_1x02_P2.54mm_Vertical | P9 |
| 1 | Dual VR C | DIP-8_W7.62mm_Socket | P10 |
| 1 | 0ZCJ0050AF2E | Fuse_1206_3216Metric | F1 |
| 2 | HALL_VR | JPR_3POS_SMLHL | JP2, JP3 |
Show 26 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 3 | PULLUP | JPR_2POS_SMLHL | JP4, JP5, JP13 |
| 1 | ARDUINO_MEGA_SHIELD | ARDUINO_MEGA_SHIELD | SHIELD1 |
| 22 | SML-310LTT86 RED | LED_0603_1608Metric | LED1, LED2, LED3, LED4, LED5, LED6, LED7, LED8 +14 |
| 18 | BAS70-02V-V-G-08 BAS70KFILM | D_SOD-523 | D1, D11, D12, D13, D15, D16, D17, D18 +10 |
| 13 | BAT54S | SOT-23 | D2, D3, D4, D5, D6, D7, D8, D9 +5 |
| 1 | B160-E3/61T B160-13-F | D_SMA | D29 |
| 1 | 1SMB5919BT3G | D_SMB | D30 |
| 15 | CL21B104KBFNNNE u1 | C_0805_2012Metric | C1, C2, C4, C6, C9, C10, C14, C16 +7 |
| 8 | CL21B224KBFNNNE u22 | C_0805_2012Metric | C3, C5, C11, C12, C15, C20, C23, C34 |
| 6 | CL21B105KBFNNNE 1u | C_0805_2012Metric | C7, C8, C18, C24, C26, C35 |
| 2 | CL21C470JBANNNC 47p | C_0805_2012Metric | C13, C21 |
| 2 | EEE-FT1H470AL 47u 50v | CP_Elec_6.3x5.4 | C17, C30 |
| 1 | CL21B103KBCNNNC u01 | C_0805_2012Metric | C28 |
| 1 | T55A476M6R3C0200 47u | CP_EIA-3216-18_Kemet-A | C31 |
| 1 | RK73H2BTTD56R0F 56r | R_1206_3216Metric | R1 |
| 1 | ERA6AEB392V 3k9 0.1% | R_0805_2012Metric | R2 |
| 1 | ERA6AEB102V 1k 0.1% | R_0805_2012Metric | R3 |
| 17 | RK73H2ATTD4700F 470r | R_0805_2012Metric | R4, R5, R8, R9, R10, R13, R16, R17 +9 |
| 5 | ERA6AEB2491V 2k49 0.1% | R_0805_2012Metric | R6, R7, R12, R15, R19 |
| 3 | RK73H2ATTD5102F 51k | R_0805_2012Metric | R11, R18, R75 |
| 19 | RK73B1JTTD272J 2k7 | R_0603_1608Metric | R14, R23, R26, R31, R34, R39, R40, R43 +11 |
| 4 | RK73H3ATTE15R0F 15r | R_2512_6332Metric | R21, R28, R29, R36 |
| 20 | RK73B1JTTD104J 100k | R_0603_1608Metric | R24, R25, R32, R33, R41, R42, R45, R46 +12 |
| 2 | RK73H2ATTD1001F 1K | R_0805_2012Metric | R59, R62 |
| 2 | RK73H2ATTD2200F 220r | R_0805_2012Metric | R60, R61 |
| 1 | RK73H2ATTD2203F 220k | R_0805_2012Metric | R76 |
Underdog design files
The KiCad project lives in the turboedge/SpeedyBoards repository on GitHub; these links point at the commit this page was built from.
Underdog: common questions
What microcontroller does the Underdog use?
The Underdog is built around the ARDUINO_MEGA_SHIELD, from the AVR/Arduino family.
How big is the Underdog PCB?
The Underdog measures 100 × 99.8 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Underdog?
202 components, from 46 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the Underdog design files?
From the turboedge/SpeedyBoards repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.
Can I use the Underdog design in my own project?
Yes, under the terms of its GPL-2.0 license, which turboedge chose for the repository.
Can I test firmware for the Underdog without the hardware?
Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug AVR/Arduino firmware against it before you order a PCB.
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