Sharp R-22AT Digit selection signal, Sound Voltage level control terminal, Key strobe signal

R-22AT

R-24AT

Pin No.	Signal	I/O		Description
					§(50Hz)
						GND
						-31(V)
41-46	P17-P12	OUT	Segment data signal.
			Signal similar to P23..
47-48	P11-P10	OUT	Digit selection signal.				H
			The relation between digit signal and digit		§(50Hz)		L
			are as follows:			GND
			Digit signal	Digit
					P11	-31(V)
			P11	1st.
			P10	2nd.	P10
			P07	3rd.
			P06	4th.	P07
			P05	5th.	P06
			P04	6th.
			Normally, one pulse is output in every ß
					P05
			period, and input to the grid of the Fluores-			GND
			cent Display.		P04	-31(V)
49-52	P07-P04	OUT	Digit selection signal.
			Signal similar to P11.
53-55	P03-P01	OUT	Segment data signal.
			Signal similar to P23.
56	P00	-	Terminal not used.
57-58	P37-P36	OUT	(Sound) Voltage level control terminal.

This terminal (P37) is to control volume level of buzzer sound with terminals P36. Since the volume level of buzzer sound depends on voltage energized, it is control level in 3 steps by combining signal levels for P37 and P36. Relationship of signal level combination to sound volume level is shown in the following table, 1~3 in the table, however, are indicated in the descending order from the maximum level of sound volume through the minimum level.

Sound Volume	P36	P37
1, (Max.)	L	L	A A : 1,(Max) 20V
2,	H	L	2,	13V
3, (Min.)	L	H	3,(Min)	7V

*At Output terminal P47, rectangular wave signal of 2.5kHz is output.

59	P35	-	Terminal not used.
60	P34	OUT	Key strobe signal.
			Signal applied to touch-key section. A pulse signal is input to P24 - P27 terminal while
			one of G-4 line keys on key matrix is touched.
61	P33	OUT	Key strobe signal.
			Signal applied to touch-key section. A pulse signal is input to P24 - P27 terminal while
			one of G-5 line keys on key matrix is touched.
62	P32	OUT	Key strobe signal.
			Signal applied to touch-key section. A pulse signal is input to P24 - P27 terminal while
			one of G-6 line keys on key matrix is touched.
63	P31	OUT	Key strobe signal.
			Signal applied to touch-key section. A pulse signal is input to P24 - P27 terminal while
			one of G-7 line keys on key matrix is touched.
64	P30	OUT	Key strobe signal.
			Signal applied to touch-key section. A pulse signal is input to P24 - P27 terminal while
			one of G-8 line keys on key matrix is touched.

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