There will be a small finite error difference in the actual position of the pads during production printing. This is the reason why these numbers are often quoted with a +/- error.
1) Pad pitch is defied as the distance between two adjacent pad centers. Use 1.22mm as stated in datasheet.
2) Use 1.93mm as calculated from the datasheet
I understand what you mean.
But the customer asked, if Module width is 15.50, the below value, which priority is higher.
1, Pad pitch is 1.22mm. 1.92mm
2, Pad pitch is 1.21mm (6-7pin, 18-19pin).1.93mm
Then I think you can go with (1).
Assuming that you indeed make a mistake on the location of Pin17, the error is negligible ((1.93-1.92)/1.92). The
reflow contact is still going to be good.
The error is caused by the unit conversion. We use mil as the unit when drawing the PCB layout. When convert it to mm, it will cause some error. You can refer to the distance with mil unit or download and refer to the .dxf file. 3D MODEL FILES FOR EZ-BLE/EZ-BT MODULES - KBA218122
The actual distance between two pads is 48mil. There is some error when convert from mil to mm. You can copy the package in the kit board and use it directly.https://www.cypress.com/documentation/development-kitsboards/cybt-343026-eval-ez-bt-module-arduino-evaluation-board