EZ-Serial Creating New GATT Service and associated characteristics

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Anonymous
Not applicable

Hi There,

I've been using the EZ-Serial module (PSoC4) for testing my platform and it has been amazing. Of late I've run into a road block while trying to create a custom GATT service and associated characteristics. I use binary mode for transacting and here are the list of commands that I sent and the responses I got.

sending command to add local service -

['0xc0', '0x19', '0x5', '0x1', '0x0', '0x28', '0x1', '0x0', '0x0', '0x0', '0x0', '0x10', '0x0', '0x0L', '0xb1L', '0xcL', '0x20L', '0x0L', '0x8L', '0x9aL', '0x9eL', '0xe2L', '0x11L', '0x15L', '0xa1L', '0x44L', '0x44L', '0x44L', '0x55L']

gatts_create_attr attr response --

['0xc0', '0x6', '0x5', '0x1', '0x10', '0x1', '0x1e', '0x0', '0x8', '0x0', '0x9c']

validity =  0x8 -- Indicates I need a characteristic definition

sending command to add local chr --

['0xc0', '0x19', '0x5', '0x1', '0x3', '0x28', '0x1', '0x0', '0x12', '0x0', '0x0', '0x10', '0x0', '0x1L', '0xb1L', '0xcL', '0x20L', '0x0L', '0x8L', '0x9aL', '0x9eL', '0xe2L', '0x11L', '0x15L', '0xa1L', '0x44L', '0x44L', '0x44L', '0x55L']

gatts_create_attr attr response --

['0xc0', '0x6', '0x5', '0x1', '0x10', '0x1', '0x1e', '0x0', '0xd', '0x0', '0xa1']

validity =  0xd  -- Indicates invalid attribute length

sending command to add local chr value attr --

['0xc0', '0xb', '0x5', '0x1', '0x1', '0x0', '0x1', '0x1', '0x12', '0x14', '0x0', '0x0', '0x0', '0x0', '0x0']

gatts_create_attr attr response --

['0xc0', '0x6', '0x5', '0x1', '0x10', '0x1', '0x1e', '0x0', '0x8', '0x0', '0x9c']

validity =  0x8

sending command to add local chr cccd attr --

['0xc0', '0xb', '0x5', '0x1', '0x2', '0x29', '0x1', '0x1', '0xa', '0x2', '0x0', '0x0', '0x0', '0x0', '0x0']

gatts_create_attr attr response --

['0xc0', '0x6', '0x5', '0x1', '0x10', '0x1', '0x1e', '0x0', '0x8', '0x0', '0x9c']

validity =  0x8

sending command to add local chr (second characteristic) --

['0xc0', '0x19', '0x5', '0x1', '0x3', '0x28', '0x1', '0x0', '0x6', '0x0', '0x0', '0x10', '0x0', '0x2L', '0xb1L', '0xcL', '0x20L', '0x0L', '0x8L', '0x9aL', '0x9eL', '0xe2L', '0x11L', '0x15L', '0xa1L', '0x44L', '0x44L', '0x44L', '0x55L']

gatts_create_attr attr response --

['0xc0', '0x6', '0x5', '0x1', '0x10', '0x1', '0x1e', '0x0', '0xd', '0x0', '0xa1']

validity =  0xd

sending command to add local chr value attr --

['0xc0', '0xb', '0x5', '0x1', '0x1', '0x0', '0x1', '0x1', '0x6', '0x14', '0x0', '0x0', '0x0', '0x0', '0x0']

gatts_create_attr attr response --

['0xc0', '0x6', '0x5', '0x1', '0x10', '0x1', '0x1e', '0x0', '0x8', '0x0', '0x9c']

validity =  0x8

-----

As you can see, I'm trying to follow pretty much the same template that the dump_db command tells me to, but still looks like somewhere the system is not happy with what I'm sending. The error on invalid attribute length while defining a new characteristic also occurs if I use the /CAC command (text mode).

My requirements -- create one service and two characteristics. On one characteristic, I want to send out notifications and want to receive data from a connected client on the other.

It will be great if you can help me resolve this issue.

Thanks.

Saranyan.

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1 Solution
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Anonymous
Not applicable

The root cause is the parameter l is not set in customer’s binary command data.

Please do following in text mode or binary mode and refer attached picture by CySmart.

/cac,t=2800,r=1,w=0,c=0,l=0010,d=0000b10c2000089a9ee21115a1444444

[C0 19 05 01 00 28 01 00 00 10 00 10 00 00 00 B1 0C 20 00 08 9A 9E E2 11 15 A1 44 44 44 53]

/cac,t=2803,r=1,w=0,c=12,l=0010,d=0100b10c2000089a9ee21115a1444444

[C0 19 05 01 03 28 01 00 12 10 00 10 00 01 00 B1 0C 20 00 08 9A 9E E2 11 15 A1 44 44 44 69]

/cac,t=0000,r=0,w=1,c=12,l=0014,d=

[C0 09 05 01 00 00 00 01 12 14 00 00 00 8F]

/cac,t=2900,r=1,w=1,c=a,l=0002,d=

[C0 09 05 01 00 29 01 01 0A 02 00 00 00 9F]

/cac,t=2803,r=1,w=0,c=12,l=0010,d=0200b10c2000089a9ee21115a1444444

[C0 19 05 01 03 28 01 00 12 10 00 10 00 02 00 B1 0C 20 00 08 9A 9E E2 11 15 A1 44 44 44 6A]

/cac,t=0000,r=0,w=1,c=6,l=0014,d=

[C0 09 05 01 00 00 00 01 06 14 00 00 00 83]

/cac,t=2900,r=1,w=1,c=a,l=0002,d=

[C0 09 05 01 00 29 01 01 0A 02 00 00 00 9F]

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