bueno todos estos micros de atmel son compatibles con el .hex que estamos usando del teensy:
32KB version: ATmega32U2
16KB version: ATmega16U2
16KB version: AT90USB162
ATmega16U2 16KB self-programming Flash Program Memory, 512-byte SRAM, 512-byte EEPROM. USB 2.0 Full Speed Device. DebugWire interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.
32KB version: ATmega32U2
AT90USB162 16KB self-programming Flash Program Memory, 512-byte SRAM, 512-byte EEPROM. USB 2.0 Full Speed Device. DebugWire interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.
ATmega32U2 32KB self-programming Flash Program Memory, 1024-byte SRAM, 1024-byte EEPROM. USB 2.0 Full Speed Device. DebugWire interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.
16KB version: ATmega16U2
ATmega16U4 16KB of self/programmable Flash Program memory, 1024-Byte EEPROM, 2.5/KB SRAM, USB 2.0 Full-speed/Low Speed Device, High-speed PWMs, 12-channel 10-bit ADC. JTAG test interface. Up to 16 MIPS Throughput at 16 MHz. 2.7 - 5.5 Volt operation.
32KB version: ATmega32U4
ATmega32U4 32KB of self-programmable Flash Program memory, 1024-Byte EEPROM, 2.5/KB SRAM, USB 2.0 Full-speed/Low Speed Device, High-speed PWMs, 12-channel 10-bit ADC. JTAG test interface. Up to 16 MIPS Throughput at 16 MHz. 2.7 - 5.5 Volt operation.
16KB version: ATmega16U4
AT90USB646 64KB self-programming Flash Program Memory, 4KB SRAM, 2048-Byte EEPROM, USB 2.0 Low Speed and Full Speed Device,8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.
64KB version with OTG Host: AT90USB647
128KB version: AT90USB1286
128KB version with OTG Host: AT90USB1287
AT90USB647 64KB self-programming Flash Program Memory, 4KB SRAM, 2048-Byte EEPROM, USB 2.0 Low speed and Full Speed On-The-Go (OTG) Host/Device, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.
64KB version without OTG Host: AT90USB646
128KB version: AT90USB1287
128KB version without OTG Host: AT90USB1286
AT90USB1286 128KB self-programming Flash Program Memory, 8KB SRAM, 4096-Byte EEPROM, USB 2.0 Low Speed and Full Speed Device,8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.
64KB version: AT90USB646
64KB version with OTG Host: AT90USB647
128KB version with OTG Host: AT90USB1287
AT90USB1287 128KB self-programming Flash Program Memory, 8KB SRAM, 4096-Byte EEPROM, USB 2.0 Low speed and Full Speed On-The-Go (OTG) Host/Device, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.
64KB version: AT90USB647
64KB version without OTG Host: AT90USB646
128KB version without OTG Host: AT90USB1286