I found an issue with the CFile.readAFloat function, in the extension settings the value is 0.5 and if i use readAFloat function to get the value in HTML5 I have 16128, I found an other method on the web:
this.val = new Float32Array(new Uint8Array([file.readAByte(), file.readAByte(),file.readAByte(), file.readAByte()]).buffer)[0];
And it work fine. Is it an issue with the CFile function or I forgot something (maybe unicode) ?