Technical references

This page is a collection of technical references surrounding Minolta/Sony flash equipment.

ISO flash shoe (old version)

The original AF series of cameras and flashes used a variant of ISO flash shoe. Here's the pinout:

ISO flash shoe, top is front

Signal Name	IO	Comment
G	G	ground (blue)
F1	→	sync / fire flash (connect G and F1) (red)
F2	↔	flash ready signal / data (white) [also: bidirectional serial data line “F2OUT”, “F2IN”]
F3	←	TTL OK signal / clock (black) [also: serial data output: “F3L” + “F3H”]
F4	→	AF assist light control (only on 9000AF, 7000AF and 5000AF)

iISO flash shoe (new version)

Later cameras and flashes used a new flash shoe which sometimes is called “iISO”. Sony calls this flash connector “Auto-lock Accessory Shoe”. Here's the pinout:

iISO flash shoe, top is front

Signal Name	IO	Comment
G	G	ground (blue)
F1	→	sync/fire flash (connect G and F1) (red)
F2	↔	flash ready signal/data (white) [also: bidirectional serial data line “F2OUT”, “F2IN”]
F3	←	TTL OK signal/clock (black) [also: serial data output: “F3L” + “F3H”]
F5/VDD1	P	flash power, regulated (+5V) & control (only on Dynax/Maxxum 3000i/Alpha 3700i)
F7/PGND	G	power ground (only on Dynax/Maxxum 3000i/Alpha 3700i)
F8/VDD0	P	flash power, unregulated (+6V) (only on Dynax/Maxxum 3000i/Alpha 3700i)

Note that F5, F7 and F8 are only present on the Dynax/Maxxum 3000i/Alpha 3700i and are used to power and control the D-316i and D-314i flashes.

Multi Interface flash shoe

A new flash shoe was introduced by Sony with the SLT-A99, NEX-6 and other cameras. It has an ISO-like layout, but with additional contacts underneath the front rim.

Multi Interface flash shoe, top is front

There are several functions on the MI shoe:

• Regulated and unregulated power, ground
• Accessory identification. These inputs determine the function of the other pins!
• Flash control
• Analog microphone
• Electronic viewfinder via an SPI interface
• GPS via an UART interface
• WLAN via an SDIO interface
• Analog audio output

The pinout (seen from top/rear) is:

23	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	24
22

(pins 23 and 24 are connected to the frame, pin 22 is the center contact)

As you can see in the table below, many pins have multiple functions, so you can only connect one type of device at a time.

Function	Pin #	IO	Signal Name	Comment
Power and ground	7	G	REG_GND	logic ground
	15	G	REG_GND	logic ground
	13	P	LOGIC_VDD	regulated power at 3.15 V
	17	P	UNREG	unregulated battery power, fused at 1.6 A
	21	G	PGND	unregulated battery ground
Accessory ID	1	←	ID3	accessory ID bit 3
	2	←	ID2	accessory ID bit 2
	3	←	ID1	accessory ID bit 1
Analog microphone	4	G	MIC_GND	microphone ground
	5	←	MIC_L	left channel
	6	←	MIC_R	right channel
	14	←	MIC_C	center/correction channel
EVF	5	→	GVIF_SDATA_N	EVF video
	6	→	GVIF_SDATA_P	EVF video
	18	→	EXT_EVF_SCK	EVF SPI clock
	19	←	EXT_EVF_SI	EVF SPI in
	20	→	EXT_EVF_SO	EVF SPI out
GPS	8	→	GPS_PWR_CTRL	GPS power control
	9	→	GPS_CTS	GPS handshake
	10	←	GPS_RTS	GPS handshake
	11	→	GPS_UART_TXD	GPS data out
	12	←	GPS_UART_RXD	GPS data in
	16	→	XGPS_RST	ext. GPS reset
WLAN	8	→	WLAN_SD_CLK	WLAN clock
	9	↔	WLAN_SD_D0	WLAN data 0
	10	↔	WLAN_SD_D1	WLAN data 1
	11	↔	WLAN_SD_D2	WLAN data 2
	12	↔	WLAN_SD_D3	WLAN data 3
	14	↔	WLAN_SD_CMD	WLAN command
	16	→	XWLAN_RST	ext. WLAN reset
Audio output	14	→	AUDIO_L	audio output, left channel
	16	→	AUDIO_R	audio output, right channel
Flash	18	←	F3	flash F3
	19	↔	F2	flash F2
	20	→	F1	flash F1
	22	X	ISO_SHOE_X	flash center contact, connected to FG when flash fires. Corresponds to F1 on older shoes.
	23	G	ISO_SHOE_FG	frame ground, also connected to REG_GND
	24	G	ISO_SHOE_FG	frame ground

Accessory types are identified by the device by connecting the ID pins either directly to logic ground (●) or via a 470 kΩ resistor to logic ground (○).

Known accessory IDs are:

ID1	ID2	ID3	accessory type
●	●	○	flash

Flash connector

This round connector is found on some flashes and all cables and connectors. Here's the pinout:

Connector, male socket

Signal Name	IO	Comment
G	G	ground (blue)
F1	→	sync / fire flash (connect G and F1) (red)
F2	↔	flash ready signal / data (white) [also: bidirectional serial data line “F2OUT”, “F2IN”]
F3	←	TTL OK signal / clock (black) [also: serial data output: “F3L” + “F3H”]

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© 2014 Michael Hohner; This page was last changed on 2014-11-18